Proportion of extended-spectrum ß-lactamase-producing Enterobacteriaceae in community setting in Ngaoundere, Cameroon

Antimicrobial Susceptibility and Characterization of Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolated from Stools of Primary Healthcare Patients in Ethiopia

Antimicrobial resistance of Escherichia coli is a growing problem in both developed and developing countries. This study aimed to investigate the phenotypic antimicrobial resistance of E. coli isolates (n = 260) isolated from the stool specimen of patients attending public health facilities in Addis Ababa and Hossana. This study also aimed to characterize phenotypically confirmed extended-spectrum beta-lactamase (ESBL)-producing E. coli isolates (n = 22) using whole-genome sequencing. Resistance to 18 different antimicrobials was assessed using the disc diffusion method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. The highest resistance rate among the E. coli isolates was found for ampicillin (52.7%), followed by trimethoprim-sulfamethoxazole (29.6%). Of all isolates, 50 (19.2%) were multidrug-resistant and 22 (8.5%) were ESBL producers. ESBL genes were detected in 94.7% of the sequenced E. coli isolates, and multiple β-lactamase genes were detected in 57.9% of the isolates. The predominant ESBL gene identified was blaCTX-M-15 (78.9%). The blaTEM-1B gene was detected in combination with other ESBL genes in 57.9% of the isolates, while only one of the sequenced isolates contained the blaTEM-1B gene alone. The blaCTX-M-3 gene was detected in three isolates. The genes blaCTX-M-15 and blaTEM-1B as well as blaCTX-M-15 and blaTEM-169 were confirmed to coexist in 52.6% and 10.5% of the sequenced E. coli isolates, respectively. In addition, blaOXA-1 was identified together with blaCTX-M-15 and blaTEM-1B in one isolate, and in one isolate, blaTEM-169 together with blaCTX-M-15 and blaTEM-1B was found. The results obtained show that measures need to be taken to reduce the spread of drug resistance and ensure the long-term use of available antimicrobials.

Molecular epidemiology of antimicrobial resistance in central africa: A systematic review

Background

In Central Africa, it is difficult to tackle antibiotic resistance, because of a lack of data and information on bacterial resistance, due to the low number of studies carried out in the field. To fill this gap, we carried out a systematic review of the various studies, and devised a molecular epidemiology of antimicrobial resistance from humans, animals and the environmental samples.

Method

A systematic search of all publications from 2005 to 2020 on bacterial resistance in Central Africa (Gabon, Cameroon, Democratic Republic of Congo, Central African Republic, Chad, Republic of Congo, Equatorial Guinea, São Tomé and Príncipe, Angola) was performed on Pubmed, Google scholar and African Journals Online (AJOL). All circulating resistance genes, prevalence and genetic carriers of these resistances were collected. The study area was limited to the nine countries of Central Africa.

Results

A total of 517 studies were identified through a literature search, and 60 studies carried out in eight countries were included. Among all articles included, 43 articles were from humans. Our study revealed not only the circulation of beta-lactamase and carbapenemase genes, but also several other types of resistance genes. To finish, we noticed that some studies reported mobile genetic elements such as integrons, transposons, and plasmids.

Conclusion

The scarcity of data poses difficulties in the implementation of effective strategies against antibiotic resistance, which requires a health policy in a 'One Health' approach.

Phenotypic characterization and epidemiology of extended-spectrum β-lactamase-producing Enterobacteriaceae strains from urinary tract infections in Garoua, Cameroon

Background and objectives

The emergence of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) is causing increased morbidity and mortality around the world as a result of therapeutic failures. ESBL-E are priority pathogens due to their multidrug resistance (MDR). In Northern Cameroon, ESBL-producing bacteria, particularly in urinary tract infections (UTIs), are being increasingly isolated. This study aimed to retrospectively determine the prevalence of multi-drug resistant ESBL strains isolated from UTIs in Northern Cameroon and to evaluate the effectiveness of the ATB UR Gallery of BioMérieux in diagnosing ESBL-E in clinical settings.

Methods

Standard microbiology protocols and statistical tools were utilized to identify ESBL-producing bacteria and characterize their phenotypic susceptibility and resistance profiles in the study population.

Results

Out of the 144 enterobacteria isolates successfully cultured, 59 (41%) were identified as MDR strains. The ATB UR EU gallery identified 33 (23%) multi-drug resistant ESBL-producing strains, while the double synergy test identified 35 strains without disc reconciliation and 38 strains after reconciliation. The most prevalent ESBL-E isolate was Escherichia coli, accounting for 77.1% of the isolates, followed by Klebsiella pneumoniae (20%) and Enterobacter aerogenes (2.9%). Additionally, the study revealed the emergence of Imipenem resistance (5.7%), a critical last-resort antibiotic. However, all ESBL strains were sensitive to Fosfomycin (FSF/FOS), demonstrating its potential as an effective therapeutic option. Moreover, 37% of the ESBL producers exhibited co-resistance to over 20 different antibiotics.

Conclusion

This study provides valuable insights into the prevalence and susceptibility patterns of ESBL-E associated with UTIs in Northern Cameroon. These insights emphasizes the importance of implementing appropriate treatment guidelines and antimicrobial stewardship measures to mitigate the spread and impact of MDR ESBL-producing strains on public health.

High level of colonization with 3rd-generation cephalosporin-resistant Enterobacterales in African community settings, Ghana

A cross-sectional survey was conducted in eight Ghanaian communities to investigate the extent of intestinal colonization with 3^rd-generation cephalosporin-resistant Enterobacterales. The study collected faecal samples and corresponding lifestyle data from 736 healthy residents to assess the occurrence of cephalosporin-resistant Escherichia coli and Klebsiella pneumoniae, with a focus on genotypes of plasmid-mediated ESBLs, AmpCs, and carbapenemases. The results showed that 371 participants (50.4%) carried 3^rd-generation cephalosporin-resistant E. coli (n=362) and K. pneumoniae (n=9). Most of these were ESBL-producing E. coli (n=352, 94.9%), carrying CTX-M genes (96.0%, n=338/352), mostly for CTX-M-15 (98.9%, n=334/338). Nine participants (1.2%) carried AmpC-producing E. coli that harboured bla_DHA-1 or blaCMY-2 genes, and two participants (0.3%) each carried a carbapenem-resistant E. coli that harboured both bla_NDM-1 and bla_CMY-2. Quinolone-resistant O25b: ST131 E. coli were recovered from six participants (0.8%) and were all CTX-M-15 ESBL-producers. Having a household toilet facility was significantly associated with a reduced risk of intestinal colonization (adjusted odds ratio, 0.71; 95% CI, 0.48-0.99; P-value=0.0095) in multivariate analysis. These findings raise serious public health concerns, and effective control of the spread of antibiotic-resistant bacteria is possible by providing better sanitary conditions for communities.

Fecal Carriage of Extended-Spectrum β-Lactamases and pAmpC Producing Enterobacterales in an Iranian Community: Prevalence, Risk Factors, Molecular Epidemiology, and Antibiotic Resistance

This study aimed to determine the prevalence and risk factors associated with intestinal carriage of extended-spectrum β-lactamases producing Enterobacterales (ESBL-PE) and plasmid-mediated AmpC β-lactamase producing Enterobacterales (AmpC-PE) in healthy children in Ardabil, Iran. A total of 305 fecal samples were collected. Isolates underwent antimicrobial susceptibility testing, phenotypic and genotypic identification of β-lactamase production, and epidemiologic molecular typing. In total, 21.5%, 1.5%, and 1.2% of volunteers were extended-spectrum β-lactamase (ESBL)-, AmpC-, and simultaneous ESBL/AmpC-PE carriers, respectively. Escherichia coli was the predominant ESBL producing bacterium (70.2%) found in ESBL-PE colonized subjects. Beyond ESBL positive isolates, bla _CTX-M group genes were the most common type (75.6%) and bla _TEM (non-bla _TEM-1 and non- bla _TEM-2) were in the second place (25.6%). Among bla _CTX-M genes, bla _CTX-M-1 (55.3%) and bla _CTX-M-15 (55.3%) were the most predominant types with equal prevalence. Some isolates were multi-enzyme producers. bla _CIT and bla _DHA genes were common AmpC type enzyme encoding genes found in AmpC-PE isolates. Most isolates produced both enzymes at the same time. The number of students in the classes was statistically associated with ESBL-PE intestinal carriage (p < 0.05). Moreover, 46 (65.7%), 3 (60%), 4 (100%), and 98 (39.8%) ESBL-, AmpC-, ESBL/AmpC, and non-ESBL/AmpC-PE isolates were multidrug-resistant, respectively. Overall, regardless of β-lactam antibiotics, 62% and 59.5% of isolates were resistant to co-trimoxazole and tetracycline, respectively. The majority of ESBL producing E. coli isolates (69.2%) belonged to phylogroup A. According to Enterobacterial repetitive intergenic consensus polymerase chain reaction, there was no clonal relatedness between isolates. This study showed a high rate of multi-resistant ESBL-PE intestinal carriage among healthy individuals in Iran.

Characteristics of Escherichia coli Isolated from Intestinal Microbiota Children of 0–5 Years Old in the Commune of Abomey-Calavi

Escherichia coli is a commensal bacterium and one of the first bacteria to colonize the digestive tract of newborns after birth. It is characterized by great versatility and metabolic flexibility that allows its survival in different niches. The present study aims at analyzing the diversity of E. coli strains isolated from the intestinal microbiota of children aged from 0 to 5 years in the commune of Abomey-Calavi in Benin. For this purpose, a descriptive and analytical cross-sectional study was conducted. A total of 135 stool samples were collected from the pediatric clinic of Abomey-Calavi. Microbiological analyses were performed according to standard microbiology analytical techniques. The molecular characterization of E. coli was performed by investigating eight genes (dinB, icdA, pabB, polB, putP, trpA, trpB, and uidA) using the PCR technique. The results showed that the average loading rate on stool samples was 3.74 × 107 CFU/g for TAMF. A total of 7 species of bacteria were identified at different proportions: Staphylococcus spp (55.36%), E. coli (14.29%), Klebsiella ornithinolytica (12.5%), Serratia odorifera (5.36%), and Enterobacter aerogenes (5.36%). Interestingly, isolated E. coli presented a resistance of 100% to cefotaxime and aztreonam. In addition, resistances of 95.24% and 50% were observed against erythromycin and nalidixic acid, respectively. The molecular characterization of the isolated E. coli strains allowed us to discover another molecular variation within the isolated strains. Genes encoding the enzymes isocitrate dehydrogenase (icd) and DNA polymerase II (polB) were detected at 96.30% in the isolated E. coli strains. Moreover, the genes encoding the enzymes beta-D-glucuronidase (uidA) and DNA polymerase (dinB) were detected at 88.89% in the isolated E. coli strains. Interestingly, 81.48%, 85.19, 92.59%, and 100% of isolated E. coli strains expressed the genes encoding the enzymes tryptophan synthase subunit A (trpA), proline permease (putP), p-aminobenzoate synthase, and tryptophan synthase subunit B (trpB), respectively. The diversity of E. coli strains reflects the importance of regulatory mechanisms in the adaptation of bacteria to the gut microbiota.

Multidrug-Resistant and Extended-Spectrum β-Lactamase (ESBL) - Producing Enterobacterales Isolated from Carriage Samples among HIV Infected Women in Yaoundé, Cameroon

The exacerbation of antimicrobial resistance (AMR) is a major public health threat worldwide. In sub-Saharan Africa, there is a scarcity of data regarding multidrug-resistant (resistance to at least one antibiotic of three or more families of antibiotics) as well as extended spectrum β-lactamase-producing Enterobacterales (ESBL-PE), isolated among clinical and asymptomatically healthy patients, especially in women living with HIV (WLHIV) despite their immunocompromised status. The overarching aim of this study was set to determine the prevalence and characterize genotypically multi-drug resistant Enterobacterales (MDR-E) and ESBL- PE isolated from vaginal swabs of WLHIV attending the Yaoundé Central Hospital, Yaoundé, Cameroon. A cross-sectional study was conducted among WLHIV during a four-month periods from 1 February to 31 May 2021. A total of 175 WLHIV, of childbearing age and under antiretroviral treatment were contacted. One hundred and twenty participants (120) were recruited and vaginal swabs were collected from them. After culture on Eosine-Methylen Blue (EMB) agar, the identification of Enterobacterales was performed using API 20E kit. A double-screening of ESBL-PE was performed using a combined disc diffusion method and ROSCO Diagnostica kits. An antibiotic susceptibility test was carried out by disc diffusion as per the Kirby-Bauer method and the β-lactamase resistance genes, bla_CTX-M, bla_{CTX-M-group1-2-9}, bla_TEM were molecularly characterized using a conventional Polymerase Chain Reaction (PCR). Overall, 30.83% (37/120) of the included WLHIV were colonized with Enterobacterales and the prevalence of vaginal carriage of MDR Enterobacterales among them was 62.16% (23/37). Among MDR-E isolates, the most prevalent species were E. coli (56.0%; 14/25) and K. pneumoniae (20.0%; 5/25). High rates of resistance to trimethoprim-sulfamethoxazole (96.0%; 24/25), amoxicillin-clavulanic acid (88.0%; 22/25) and gentamicin (72%; 18/25) were observed. The resistance mechanisms detected among these isolates were ESBL (48.0%; 12/25), ESBL+ porin loss (8.0%; 2/25), ESBL+AmpC (24%; 6/25), with bla_CTX-M, bla_{CTX-M-group-1,2,9} being identified at 48.0% (12/25) for each of them and bla_TEM at 72.0% (18/25). Our findings confirm the high-prevalence of MDR as well as ESBL-PE isolated in WLHIV, and suggest that a real time monitoring system of antimicrobial resistant bacteria coupled with the reinforcement of infection prevention control (IPC) strategies are needed to sustainably contain these life-threatening pathogens especially in the most vulnerable populations.

GENOMIC CHARACTERIZATION OF MULTIDRUG-RESISTANT EXTENDED-SPECTRUM β-LACTAMASE-PRODUCING ESCHERICHIA COLI AND KLEBSIELLA PNEUMONIAE FROM CHIMPANZEES (PAN TROGLODYTES) FROM WILD AND SANCTUARY LOCATIONS IN UGANDA

Farm and wild animals may serve as reservoirs of antimicrobial-resistant bacteria of human health relevance. We investigated the occurrence and genomic characteristics of extended spectrum β-lactamase (ESBL)-producing bacteria in Ugandan chimpanzees (Pan troglodytes) residing in two environments with or without close contact to humans. The ESBL-producing Escherichia coli and Klebsiella pneumoniae were isolated from fecal material of chimpanzees from Budongo Forest and Ngamba Island Chimpanzee Sanctuary in Uganda and were more commonly isolated from chimpanzees in Ngamba Island Chimpanzee Sanctuary, where animals have close contact with humans. Selected ESBL isolates (E. coli n=9, K. pneumoniae n=7) were analyzed by whole-genome sequencing to determine the presence of resistance genes, as well as sequence type and virulence potential; the blaCTX-M-15 gene was present in all strains. Additionally, the ESBL genes blaSHV-11 and blaSHV-12 were found in strains in the study. All strains were found to be multidrug resistant. The E. coli strains belonged to four sequence types (ST2852, ST215, ST405, and ST315) and the K. pneumoniae strains to two sequence types (ST1540 and ST597). Virulence genes did not indicate that strains were of common E. coli pathotype, but strains with the same sequence types as isolated in the current study have previously been reported from clinical cases in Africa. The findings indicate that chimpanzees in close contact with humans may carry ESBL bacteria at higher frequency than those in the wild, indicating a potential anthropogenic transmission.

Carriage Prevalence of Extended-Spectrum β-Lactamase Producing Enterobacterales in Outpatients Attending Community Health Centers in Blantyre, Malawi

Antimicrobial resistance due to extended-spectrum β-lactamase (ESBL) production by Enterobacterales is a global health problem contributing to increased morbidity and mortality, particularly in resource-constrained countries. We aimed to determine the prevalence of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) in community patients in Blantyre, Malawi. Clinical samples were collected from 300 patients and screened for ESBL-E using a CHROMagar^TM ESBL medium. Confirmation of ESBL production was done by a combination disk test (CDT). The prevalence of community-acquired ESBL-E was 16.67% (50/300, 95% CI = 12.43–20.91%). The most common ESBL-E species isolated was Escherichia coli (66%). All ESBL-E isolates were resistant to Trimethoprim-Sulfamethoxazole except for 2% of E. coli. Besides this, all ESBL-E were susceptible to Imipenem and only 4% were resistant to Meropenem. No patients with a positive ESBL-E phenotype had a history of hospital admission in the last three months, and the carriage of ESBL-E was neither associated with the demographic nor the clinical characteristics of participants. Our findings reveal a low presence of ESBL-E phenotypes in community patients. The low prevalence of ESBL-E in the community settings of Blantyre can be maintained if strong infection and antimicrobial use-control strategies are implemented.

High ESBL-E colonization rate among children in Gabon: a follow-up study

A previous study conducted in Gabon, Central Africa, in 2010/11 found a high colonization rate with extended-spectrum β-lactamase-producing enterobacterales (ESBL-E) among children of ~34 %. Eight years later, we aimed to reassess the ESBL-E rate and previously identified risk factors for colonization in children from Gabon. We conducted a cross-sectional cohort study in 2018 on 92 outpatients under 5 years of age with diarrhoea in Lambaréné, Gabon, in whom a rectal swab was obtained at the initial medical encounter (baseline). Fifty-eight of these provided a further rectal swab 1 week afterwards. ESBL-E colonization was assessed [following the European Committee on Antimicrobial Susceptibility Testing (EUCAST)], and in confirmed ESBL-E isolates the susceptibility to meropenem and the prevalence of the most abundant ESBL genes, bla _CTX-M, bla _SHV, and bla _TEM, were investigated. At baseline, the ESBL-E colonization rate was 57 % (52/92; 95 % CI: 46-67). Hospitalization during the previous year, chicken consumption in the past week and young age were identified as independent risk factors for ESBL-E colonization at baseline. On day 7, the ESBL-E carriage rate was 72 % (42/58; 95 % CI: 59-83). All ESBL-E isolates (n=293) were susceptible to meropenem and bla _CTX-M was the most frequently detected β-lactamase gene. The ESBL-E colonization rate among children from Gabon is alarmingly high, with indications of further increase over recent years. While all ESBL-E strains remain currently susceptible to meropenem, in practice no adequate treatment is available locally for severe infections with such isolates. It is thus of the utmost importance to invest in improved hospital infection prevention and control measures to combat ESBL-E effectively.

Colonization with multiresistant bacteria in acute hospital care: the association of prior antibiotic consumption as a risk factor

BACKGROUND

Antibiotic resistance poses a worldwide threat and knowledge concerning risk factors for colonization with multiresistant bacteria (MRB) is limited.

OBJECTIVES

To examine the impact of prior antibiotic consumption on MRB colonization, with focus on type of antibiotic and timeline between antibiotic prescription and MRB colonization.

METHODS

A nationwide case-control study was conducted and adults visiting emergency departments were invited to participate. All patients were swabbed in the throat, nose and rectum, and analysed for colonization with ESBL-producing Enterobacteriaceae (ESBL-E), MRSA, carbapenemase-producing enterobacteria and VRE. Antibiotic history 2 years prior to enrolment was collected at an individual level through a national register. Multivariate analyses were performed to examine the association between antibiotic consumption and MRB status. A subgroup analysis of ESBL-E-colonized cases was made.

RESULTS

We included 256 patients colonized with MRB and 4763 controls. In the 2 years prior to study inclusion, 77% of cases and 68% of controls had at least one antibiotic prescription (P = 0.002). We found a significant increase in risk of colonization with ESBL-E if penicillins (OR = 1.58-1.65) or fluoroquinolones (OR = 2.25-6.15) were prescribed. The analysis of all MRB-colonized patients showed similar results. An assessment of the timeline showed a significant increase in risk of colonization up to 2 years after exposure to penicillins, fluoroquinolones and macrolides.

CONCLUSIONS

The prevalence of ESBL-E colonization was related to fluoroquinolone, macrolide and penicillin consumption for at least 2 years after antibiotic treatment.

The global prevalence and trend of human intestinal carriage of ESBL-producing Escherichia coli in the community

OBJECTIVES

Intestinal colonization by ESBL Escherichia coli and its association with community-acquired MDR infections is of great concern. This review determined the worldwide prevalence of human faecal ESBL E. coli carriage and its trend in the community over the past two decades.

METHODS

A systematic literature search was conducted using PubMed, EMBASE and Google Scholar to retrieve articles published between 1 January 2000 and 13 February 2020 that contained data on the prevalence of faecal carriage of ESBL E. coli among healthy individuals. A cumulative (for the whole period) meta-analysis was used to estimate the global and regional pooled prevalence rates. Articles were grouped into study periods of 3 years, and subgroup meta-analyses were undertaken to examine the global pooled prevalence over time.

RESULTS

Sixty-two articles covering 29 872 healthy persons were included in this meta-analysis. The cumulative (2003-18) global pooled prevalence of ESBL E. coli intestinal carriage in the community was 16.5% (95% CI 14.3%-18.7%; P  <  0.001). The pooled prevalence showed an upward trend, increasing from 2.6% (95% CI 1.6%-4.0%) in 2003-05 to 21.1% (95% CI 15.8%-27.0%) in 2015-18. Over the whole period, the highest carriage rate was observed in South-East Asia (27%; 95% CI 2.9%-51.3%), while the lowest occurred in Europe (6.0%; 95% CI 4.6%-7.5%).

CONCLUSIONS

Globally, an 8-fold increase in the intestinal carriage rate of ESBL E. coli in the community has occurred over the past two decades. Prevention of its spread may require new therapeutic and public health strategies.

Prevalence and Characterization of Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae in Major Hospitals in Gabon

In Gabon, few data exist on extended-spectrum beta-lactamases-producing Enterobacteriaceae (ESBL-PE). This study investigated ESBL-PE prevalence and the associated resistance genes in clinical samples (n = 5,956) and anal swabs (n = 78) analyzed in eight hospitals and a medical analysis laboratory in Gabon from January 2016 to March 2018. Matrix-Assisted Laser Desorption Ionization-Time Of Flight (MALDI-TOF) mass spectrometry analysis identified 790 Enterobacteriaceae isolates (n = 712 clinical samples and n = 78 fecal samples). ESBL-PE prevalence (Müller-Hinton agar disk diffusion method and double-disk synergy test) was 11.8% (84/712) in clinical samples (15.5% from inpatients and 7.1% from outpatients; p < 0.05) and 16.7% (13/78) in carriage isolates. Most ESBL-PE were isolated from urine samples (46/84). In clinical and carriage ESBL-PE isolates, Escherichia coli was predominant (42.8% and 61.5%; phylogroups A, B1, B2, and D), followed by Klebsiella pneumoniae (41.7% and 23.1%). Multiplex PCR and bi-directional sequencing showed that CTX-M group 1 (blaCTX-M-15) was predominant in clinical and carriage ESBL-PE (94% and 92.3%) among which 85.7% and 92.3% also harbored one to three β-lactamase-encoding genes (blaTEM-1, blaOXA-1, or blaSHV-1). Resistance genes were detected in all hospitals in Gabon. ESBL-PE prevalence in Gabon has not reached alarming levels yet, but corrective and monitoring measures are needed to curb their emergence.

Fecal carriage of extended spectrum beta-lactamase producing Enterobacteriaceae among HIV infected children at the University of Gondar Comprehensive Specialized Hospital Gondar, Ethiopia

Background

Human immunodeficiency virus (HIV) and extended spectrum beta lactamase (ESBL) producing Enterobacteriaceae infections are the major challenges in sub-Saharan Africa. Data on the carriage rate of ESBL producing Enterobacteriaceae among HIV infected children is lacking in Ethiopia. Hence this study was aimed to investigate fecal carriage of ESBL producing Enterobacteriaceae among HIV infected children at the University of Gondar comprehensive Specialized Hospital.

Methods

A cross-sectional study was conducted among HIV infected children from January to April 2020. Stool specimens were collected from 161 study participants by convenient sampling and cultured on MacConkey agar. Biochemical identification, antimicrobial susceptibility testing including ESBL production were carried out. Data were analyzed by SPSS version-20 and P-value < 0.05 on multivariate logistic regression analysis was regarded as statistically significant.

Results

From a total of 161 study participants male to female ratio was 1:1.1. Moreover; 96.3% of participants were in HIV stage-I and 90.1% had at least a year highly active antiretroviral therapy exposure. A total of 186 Enterobacteriaceae, with E. coli 60% and K. pneumonia 16.13% predominance were isolated from 161 participants. Majority of isolates were most resistant to amoxicillin (95.1%) and sensitive to CHL (94.1%), CXT (91.4%) and CAZ (91.4%). There were 71(38.17%) multidrug resistant isolates, 13 of which were also ESBL producers. The overall ESBL carriage rate was 32/161 (19.9%). History of antibiotic use was the independent factor associated with ESBL carriage (AOR 3.23 (95% CI 1.054–9.88)) and P-value of 0.04.

Conclusion

ESBL carriage rate of HIV infected children was considerable. Previous antibiotic use was the independent factor. Regular screening for antibiotic resistance on HIV patients before prescription and large-scale antibiotic resistance survey including healthy community may be important.

Intestinal Carriage of Extended-Spectrum β-Lactamase- (ESBL-) Possessing Escherichia coli and Klebsiella Species among Nepalese Health Science and Non-Health Science Students

Infections due to extended-spectrum β-lactamase- (ESBL-) producing Gram-negative bacteria have led to increased mortality, morbidity, and economic burden worldwide. These bacteria can colonize the healthy intestine of human beings and can disseminate in communities and hospital. This study aimed to investigate the prevalence of fecal carriage of ESBL-producing Escherichia coli and Klebsiella species among health science (HS) and non-health science (NHS) students. This descriptive cross-sectional study was conducted on 104 HS and 104 NHS students in which one stool sample from each student was collected and processed for bacterial culture and sensitivity testing according to standard bacteriological procedures. Each morphotype was identified and characterized phenotypically. The antimicrobial sensitivity profile of bacterial isolates was determined by the Kirby–Bauer disk diffusion technique. ESBL production was tested by combination disk method as recommended by the Clinical and Laboratory Standards Institute. Out of 208 stool samples, E. coli and Klebsiella spp. were recovered from 203 (86.8%) and 31 (13.2%) stool samples, respectively. Among those 234 isolates, 69 were positive for ESBL which included E. coli (n = 66, 95.7%) and Klebsiella spp. (n = 3, 4.3%). Fifty (42.4%) out of 118 isolates from HS students and 19 (16.4%) out of 116 from NHS students were colonized by ESBL-producers. Compared to non-ESBL producers, a higher number of ESBL-producing isolates were resistant to ciprofloxacin (14.5% vs. 1.8%, p < 0.001), cotrimoxazole (59.4% vs. 16.4%, p < 0.001), and amikacin (10.1% vs 4.2%, p < 0.001). All E. coli and Klebsiella species isolates were susceptible to meropenem. The prevalence of fecal carriage of ESBL-producing bacteria was higher in HS students; however, there was a considerable number of these strains colonizing NHS students as well. This “iceberg phenomenon” of asymptomatic carriage of ESBL-producing pathogens might act as a source of infection in both the community and hospitals. Therefore, surveillance of carriage of drug-resistant bacteria should be performed regularly.

Prevalence of Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae in Ethiopia: A Systematic Review and Meta-Analysis

Background

Antimicrobial resistance especially caused by extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) has become a global public health concern. Globally, these isolates have remained the most important causes of several infections and associated mortality. Their rapid spread in Ethiopia is associated with a lack of regular surveillance and antibiotic stewardship programs. Isolates of ESBL-PE from different regions of Ethiopia were searched exhaustively. However, published data regarding the pooled estimate of ESBL-PE are not conducted in Ethiopia. For this reason, we systematically reviewed laboratory-based studies to summarize the overall pooled prevalence of the isolates recovered from various human specimens.

Methods

An exhaustive literature search was carried out using the major electronic databases including PubMed, Web of Science, MEDLINE, EMBASE, CINAHL, Google Scholar, Cochrane Library, Scopus, and Wiley Online Library to identify potentially relevant studies without date restriction. Original articles which address the research question were identified, screened, and included using the PRISMA follow diagram. Data extraction form was prepared in Microsoft Excel, and data quality was assessed by using 9-point Joanna Briggs Institute critical appraisal tools. Then, data were exported to STATA 16.0 software for analyses of pooled estimation of outcome measures. Estimation of outcome measures at 95% confidence interval was performed using Der-Simonian-Laird's random-effects model. Finally, results were presented via text, figures, and tables.

Results

A comprehensive electronic database literature search has yielded a total of 86 articles. Among the total, 68 original articles were excluded after the review process. A total of 18 studies with 1191 bacterial isolates recovered from 7919 various clinical samples sizes were included for systematic review and meta-analysis. In this study, the pooled prevalence of ESBL-PE was 18% (95% CI: 9–26). Nine out of the total (50%) reviewed articles were studied using the combination disk test. Likewise, E. coli and K. pneumoniae (50% both) were the predominant isolates of ESBL-PE in addition to other isolates such as Salmonella spp. and Shigella spp.

Conclusion

This meta-analysis has shown a low pooled estimate of ESBL-PE in Ethiopia.

Antimicrobial Resistance in Enterobacterales and Its Contribution to Sepsis in Sub-saharan Africa

Antibiotic resistant Enterobacterales (formerly Enterobactereaceae) are a growing threat to Sub-Saharan Africa. Genes causing antibiotic resistance are easily spread between the environment and humans and infections due to drug resistant organisms contribute to sepsis mortality via delayed time to appropriate antimicrobial therapy. Additionally, second or third-line antibiotics are often not available or are prohibitively expensive in resource-constrained settings leading to limited treatment options. Lack of access to water and sanitation facilities, unregulated use of antibiotics, and malnutrition are contributors to high rates of antibiotic resistance in the region. Improvements in the monitoring of drug resistant infections and antibiotic stewardship are needed to preserve the efficacy of antibiotics for the future.

Epidemiology and prevalence of extended-spectrum β-lactamase- and carbapenemase-producing Enterobacteriaceae in humans, animals and the environment in West and Central Africa

Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) and carbapenemase-producing Enterobacteriaceae (CPE) are widespread. Here we used the 'One Health' approach to determine knowledge gaps on ESBL-E and CPE in West and Central Africa. We searched all articles on ESBL-E and CPE in these African regions published in PubMed, African Journals Online and Google Scholar from 2000 onwards. Among the 1201 articles retrieved, we selected 165 studies (West Africa, 118; Central Africa, 47) with data from 22 of the 26 West and Central Africa countries. Regarding the settings, 136 articles focused only on humans (carriage and/or infection), 6 articles on humans and animals, 13 on animals, 1 on humans and the environment, 8 on the environment and 1 on humans, animals and environments. ESBL-E prevalence ranged from 11-72% in humans and 7-79% in aquatic environments (wastewater). In animals, ESBL-E prevalence hugely varied: 0% in cattle, 11-36% in chickens, 20% in rats, 21-71% in pigs and 32-75% in dogs. The bla_CTX-M-15 gene was the predominant ESBL-encoding gene and was associated with plasmids of incompatibility groups F, H, K, Y, N, I1 and R. CPE were studied only in humans. Class B metallo-β-lactamases (NDM) and class D oxacillinases (OXA-48 and OXA-181) were the most common carbapenemases. Our results show major knowledge gaps, particularly on ESBL and CPE in animals and the environment, that might limit antimicrobial resistance management in these regions. The results also emphasise the urgent need to improve active surveillance programmes in each country and to support antimicrobial stewardship.

Prevalence of extended-spectrum beta-lactamase-producing enterobacterial urinary infections and associated risk factors in small children of Garoua, Northern Cameroon

Introduction

the emergence of extended-spectrum beta-lactamase-producing Entero bacteriaceae (E-ESBLs) is currently a major public health problem in the world and, in particular, in developing countries. In Cameroon, data on E-ESBLs are rare, especially in Garoua and in the northern region of the country. The objective of this study is to document the epidemiology of E-ESBL infections in small children and to explore their associations with possible risk factors.

Methods

this was a cross-sectional, descriptive study conducted from June 14 to September 30, 2018, including small children with suspected urinary tract infections (UTI) attending the outpatient pediatric departments of two health facilities in the city of Garoua. Urine samples were analyzed at the Bacteriology Laboratory of the Pasteur Center of Cameroon, Annex Garoua. Bacterial culture was carried out on Bio-Rad UriSelect® chromogenic agar and the identification was confirmed by bioMérieux API 20E. The antibiotic susceptibility was determined using the bioMérieux ATB UR gallery and the ESBL phenotype was detected by the double disk synergy method according to the CA-SFM 2013 recommendations. The data was analyzed with the R Statistical Software version 2.15.2.

Results

a total of 57 urine samples were collected from children aged from one month to two years, 37 boys and 20 girls. Bacteria were detected by culture in 20 samples: Escherichia coliwas the most frequently (75 %) isolated species followed by Klebsiella pneumoniae(25%). More than half of the infected samples (55%) contained E-ESBL. The presence of an ESBL was significantly associated with previous antibiotic intake up to 3 months prior current UTI (p=0.01664). The E-ESBL strains showed co-resistance to different antibiotics.

Conclusion

this study reveals the important dissemination of E-ESBLs among small children in the community and a high rate of co-resistance to the different antibiotic families commonly used.

Carriage of Extended-Spectrum-β-Lactamase- and AmpC-β-Lactamase-Producing Enterobacteriaceae (ESBL-PE) in Healthy Community and Outpatient Department (OPD) Patients in Nepal

Background

Extended-spectrum β-lactamase (ESBL)- and AmpC-β-lactamase (ESBL)- and AmpC-Enterobacteriaceae have recently emerged as a public threat in the treatment of nosocomial as well as community-acquired infections. Very little information is currently available about its existence in Nepal. We, therefore, aim to determine the prevalence of ESBL and AmpC-β-lactamase (ESBL)- and AmpC-Enterobacteriaceae have recently emerged as a public threat in the treatment of nosocomial as well as community-acquired infections. Very little information is currently available about its existence in Nepal. We, therefore, aim to determine the prevalence of ESBL and AmpC-

Methods

During a 6-month period (November 2014–April 2015), a total of 190 stool specimens from 190 participants were obtained from different population. Of the total 260 fecal isolates, 152 from outpatient department (OPD) and 108 from healthy volunteer were collected. Stool specimens were cultured and enterobacterial isolates were subjected to antimicrobial susceptibility tests according to the standard microbiologic guidelines. ESBL was screened using ceftazidime (CAZ, 30 μg) and cefotaxime (CTX, 30 μg) and cefotaxime (CTX, 30 β-lactamase (ESBL)- and AmpC-

Results

The prevalence of ESBL, AmpC-β-lactamase (ESBL)- and AmpC-β-lactamase (ESBL)- and AmpC-Enterobacteriaceae have recently emerged as a public threat in the treatment of nosocomial as well as community-acquired infections. Very little information is currently available about its existence in Nepal. We, therefore, aim to determine the prevalence of ESBL and AmpC-E. coli was 70.2% followed by K. pneumoniae (12.7%), and among AmpC-β-lactamase (ESBL)- and AmpC-E. coli was 70.2% followed by E. coli was 70.2% followed by K. pneumoniae (12.7%), and among AmpC-K. pneumoniae (12.7%), and among AmpC-C. freundii 2/7 (28.57%) were detected highest among AmpC-β-lactamase (ESBL)- and AmpC-

Conclusion

Our study revealed a high prevalence of ESBL- and AmpC-β-lactamase-producing enteric pathogen in Nepalese OPD and healthy population. The significant increase of these isolates and increased rate of drug resistance indicates a serious threat that stress the need to implement the surveillance system and a proper control measure so as to limit the spread of ESBL-producing Enterobacteriaceae (ESBL-PE) in both OPD as well as in community. Therefore, healthcare providers need to be aware that ESBL- and AmpC-β-lactamase-producing strains are not only circulating in hospital environments but also in the community and should be dealt with accordingly.β-lactamase (ESBL)- and AmpC-Enterobacteriaceae have recently emerged as a public threat in the treatment of nosocomial as well as community-acquired infections. Very little information is currently available about its existence in Nepal. We, therefore, aim to determine the prevalence of ESBL and AmpC-β-lactamase (ESBL)- and AmpC-

Fecal carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae in hospital and community settings in Chad

Background

Fecal carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) remains poorly documented in Africa. The objective of this study was to determine the prevalence of ESBL-PE fecal carriage in Chad.

Methods

In total, 200 fresh stool samples were collected from 100 healthy community volunteers and 100 hospitalized patients from January to March 2017. After screening using ESBL-selective agar plates and species identification by MALDI-TOF mass spectrometry, antibiotic susceptibility was tested using the disk diffusion method, and ESBL production confirmed with the double-disc synergy test. The different ESBL genes in potential ESBL-producing isolates were detected by PCR and double stranded DNA sequencing. Escherichia coli phylogenetic groups were determined using a PCR-based method.

Results

ESBL-PE fecal carriage prevalence was 44.5% (51% among hospitalized patients vs 38% among healthy volunteers; p < 0.05). ESBL-producing isolates were mostly Escherichia coli (64/89) and Klebsiella pneumoniae (16/89). PCR and sequencing showed that 98.8% (87/89) of ESBL-PE harbored bla_CTX-M genes: bla_CTX-M-15 in 94.25% (82/87) and bla_CTX-M-₁₄ in 5.75% (5/87). Phylogroup determination by quadruplex PCR indicated that ESBL-producing E. coli isolates belonged to group A (n = 17; 27%), C (n = 17; 27%), B2 (n = 9; 14%), B1 (n = 8; 13%), D (n = 8; 13%), E (n = 1; 1.6%), and F (n = 1; 1.6%). The ST131 clone was identified in 100% (9/9) of E. coli B2 strains.

Conclusions

The high fecal carriage rate of ESBL-PE associated with CTX-M-15 in hospital and community settings of Chad highlights the risk for resistance transmission between non-pathogenic and pathogenic bacteria.

Gut mucosal colonisation with extended-spectrum beta-lactamase producing Enterobacteriaceae in sub-Saharan Africa: a systematic review and meta-analysis

Background: Extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-E) threaten human health; and, in areas of sub-Saharan Africa (sSA) where carbapenems are not available, may render ESBL-E infections untreatable. Gut mucosal colonisation probably occurs before infection, making prevention of colonisation an attractive target for intervention, but the epidemiology of ESBL-E in sSA is poorly described.

Objectives: Describe ESBL-E colonisation prevalence in sSA and risk factors associated with colonisation.

Methods: Studies included were prospective cross-sectional or cohort studies reporting gut mucosal ESBL-E colonisation in any population in sSA. We searched PubMed and Scopus on 18 December 2018. We summarise the range of prevalence across sites and tabulated risk factors for colonisation. The protocol was registered (Prospero ID CRD42019123559).

Results: From 2975 abstracts we identified 32 studies including a total of 8619 participants from a range of countries and settings. Six studies were longitudinal; no longitudinal studies followed patients beyond hospital discharge.  Prevalence varied between 5 and 84% with a median of 31%, with a relationship to setting: pooled ESBL-E colonisation in community studies was 18% (95% CI 12 to 28, 12 studies); in studies recruiting people at admission to hospital colonisation was 32% (95% CI 24 to 41% 8 studies); and for inpatients, colonisation was 55% (95% CI 49 to 60%, 7 studies). Antimicrobial use was associated with increased risk of ESBL-E colonisation, and protected water sources or water treatment by boiling may reduce risk.

Conclusions: ESBL-E colonisation is common in sSA, but how people become carriers and why is not well understood. To inform the design of interventions to interrupt transmission in this setting requires longitudinal, community studies.

Gut mucosal colonisation with extended-spectrum beta-lactamase producing Enterobacteriaceae in sub-Saharan Africa: a systematic review and meta-analysis

Background: Extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-E) threaten human health; and, in areas of sub-Saharan Africa (sSA) where carbapenems are not available, may render ESBL-E infections untreatable. Gut mucosal colonisation probably occurs before infection, making prevention of colonisation an attractive target for intervention, but the epidemiology of ESBL-E in sSA is poorly described. Objectives: Describe ESBL-E colonisation prevalence in sSA and risk factors associated with colonisation. Methods: Studies included were prospective cross-sectional or cohort studies reporting gut mucosal ESBL-E colonisation in any population in sSA. We searched PubMed and Scopus on 18 December 2018. We summarise the range of prevalence across sites and tabulated risk factors for colonisation. The protocol was registered (Prospero ID CRD42019123559). Results: From 2975 abstracts we identified 32 studies including a total of 8619 participants from a range of countries and settings. Six studies were longitudinal; no longitudinal studies followed patients beyond hospital discharge.  Prevalence varied between 5 and 84% with a median of 31%, with a relationship to setting: pooled ESBL-E colonisation in community studies was 18% (95% CI 12 to 28, 12 studies); in studies recruiting people at admission to hospital colonisation was 32% (95% CI 24 to 41% 8 studies); and for inpatients, colonisation was 55% (95% CI 49 to 60%, 7 studies). Antimicrobial use was associated with increased risk of ESBL-E colonisation, and protected water sources or water treatment by boiling may reduce risk. Conclusions: ESBL-E colonisation is common in sSA, but how people become carriers and why is not well understood. To inform the design of interventions to interrupt transmission in this setting requires longitudinal, community studies.

Antimicrobial resistance from a one health perspective in Cameroon: a systematic review and meta-analysis

Background

Antimicrobial resistance (AMR) is widely acknowledged as a global health problem, yet in many parts of the world its magnitude is not well elucidated. A baseline assessment of the AMR prevalence is a priority for implementation of laboratory-based AMR surveillance This review, focused on a One health approach, aimed at describing the current status of AMR in Cameroon.

Methods

PubMed, Google Scholar and African Journals Online databases were searched for articles published in English and French in accordance with the PRISMA guidelines. Retrieval and screening of article was done using a structured search string with strict inclusion/exclusion criteria. Free-text and grey literature were obtained by contacting the authors directly. The pooled prevalence and 95% confidence intervals were calculated for each pathogen–antibiotic pairs using random-effects models.

Result

Amongst 97 full-text articles reviewed, 66 met the eligibility criteria. The studies originated from the Centre (24; 36.4%), South-West (16; 24.2%), West (13; 19.7%), Littoral (9; 13.6%) and other (4; 6.1%) regions of Cameroon. These studies reported AMR in human (45; 68.2%), animals (9; 13.6%) and the environment (12; 18.2%). Overall, 19 species of bacteria were tested against 48 antibiotics. These organisms were resistant to all classes of antibiotics and showed high levels of multidrug resistance. Escherichia coli, Klebsiella pneumoniae and Staphylococcus spp were reported in 23, 19 and 18 of the human studies and revealed multidrug resistance (MDR) rates of 47.1% [95% CI (37.3–57.2%)], 51.0% [95% CI (42.0–59.9)] and 45.2% [95% CI (38.0–54.7)], respectively. Salmonella spp was reported in 6 of the animal studies and showed a MDR rate of 46.2% [95% CI (39.2–53.5%)] while Staphylococcus spp in 8 of environment studies showed MDR rate of 67.1% [95% CI (55.2–77.2%)].

Conclusion

This review shows that resistance to commonly prescribed antibiotics in Cameroon is high. The findings emphasize the urgent need to address gaps in the standardization of AMR diagnostics, reporting and use of available information to optimize treatment guidelines for the arsenal of antibiotics. Effective AMR surveillance through continued data sharing, large-scale collaboration, and coordination of all stakeholders is essential to understand and manage the AMR national burden.

Isolation of Extended-Spectrum β-lactamase- (ESBL-) Producing Escherichia coli and Klebsiella pneumoniae from Patients with Community-Onset Urinary Tract Infections in Jimma University Specialized Hospital, Southwest Ethiopia

Background

Klebsiella pneumoniae and Escherichia coli are the major extended-spectrum β-lactamase- (ESBL-) producing organisms increasingly isolated as causes of complicated urinary tract infections and remain an important cause of failure of therapy with cephalosporins and have serious infection control consequence.

Objective

To assess the prevalence and antibiotics resistance patterns of ESBL-producing Escherichia coli and Klebsiella pneumoniae from community-onset urinary tract infections in Jimma University Specialized hospital, Southwest Ethiopia, 2016.

Methodology

A hospital-based cross-sectional study was conducted, and a total of 342 urine samples were cultured on MacConkey agar for the detection of etiologic agents. Double-disk synergy (DDS) methods were used for detection of ESBL-producing strains. A disc of amoxicillin + clavulanic acid (20/10 µg) was placed in the center of the Mueller–Hinton agar plate, and cefotaxime (30 µg) and ceftazidime (30 µg) were placed at a distance of 20 mm (center to center) from the amoxicillin + clavulanic acid disc. Enhanced inhibition zone of any of the cephalosporin discs on the side facing amoxicillin + clavulanic acid was considered as ESBL producer.

Results

In the current study, ESBL-producing phenotypes were detected in 23% (n = 17) of urinary isolates, of which Escherichia coli accounts for 76.5% (n = 13) and K. pneumoniae for 23.5% (n = 4). ESBL-producing phenotypes showed high resistance to cefotaxime (100%), ceftriaxone (100%), and ceftazidime (70.6%), while both ESBL-producing and non-ESBL-producing isolates showed low resistance to amikacin (9.5%), and no resistance was seen with imipenem. In the risk factors analysis, previous antibiotic use more than two cycles in the previous year (odds ratio (OR), 6.238; 95% confidence interval (CI), 1.257–30.957; p = 0.025) and recurrent UTI more than two cycles in the last 6 months or more than three cycles in the last year (OR, 7.356; 95% CI, 1.429–37.867; p = 0.017) were found to be significantly associated with the ESBL-producing groups.

Conclusion

Extended-spectrum β-lactamases- (ESBL-)producing strain was detected in urinary tract isolates. The occurrence of multidrug resistance to the third-generation cephalosporins, aminoglycosides, fluoroquinolones, trimethoprim-sulfamethoxazole, and tetracyclines is more common among ESBL producers. Thus, detecting and reporting of ESBL-producing organisms have paramount importance in the clinical decision-making.

Prevalence of extended-spectrum-β-lactamase-producing Enterobacteriaceae: first systematic meta-analysis report from Pakistan

Background

South-Asia is known as a hub for multidrug-resistant (MDR) bacteria. Unfortunately, proper surveillance and documentation of MDR pathogens is lacking in Pakistan. The alarming increase in the prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is a serious problem. From this perspective, we analysed published data regarding ESBL-producing Enterobacteriaceae in different regions of Pakistan.

Methods

A meta-analysis was performed to determine the prevalence of ESBL-producing Enterobacteriaceae in Pakistan. A Web-based search was conducted in electronic databases, including PubMed, Scopus and PakMedi Net (for non-indexed Pakistani journals). Articles published (in either indexed or non-indexed journals) between January 2002 and July 2016 were included in the study. Relevant data were extracted, and statistical analysis was performed using the Metaprop command of STATA version 14.1.

Results

A total of 68 studies were identified from the electronic data base search, and 55 of these studies met our inclusion criteria. Pakistan’s overall pooled proportion of ESBL-producers was 0.40 (95% CI: 0.34–0.47). The overall heterogeneity was significant (I2 = 99.75%, p < 0.001), and significant ES = 0 (Z = 18.41, p < 0.001) was found. OXA, SHV, TEM and CTX-M were the most commonly found gene variants for ESBLs in these studies.

Conclusion

The prevalence of ESBL-producing Enterobacteriaceae is high in Pakistan. Little is known about the annual frequency of ESBLs and their prevalence in different provinces of Pakistan. No data are available regarding ESBL frequency in Baluchistan. This underscores an urgent demand for regular surveillance to address this antimicrobial resistance problem. Surveillance to better understand the annual ESBL burden is crucial to improve national and regional guidelines.

Prevalence and risk factors for CTX-M gram-negative bacteria in hospitalized patients at a tertiary care hospital in Kilimanjaro, Tanzania

Emergence and spread of extended spectrum beta-lactamase (ESBL)-producing gram-negative bacteria, mainly due to CTX-M, is a major global public health problem. Patients infected with ESBL-producing gram-negative bacteria have an increased risk of treatment failure and death. We investigated the prevalence and risk factors for CTX-M gram-negative bacteria isolated from clinical specimens of patients hospitalized at a tertiary care hospital in Kilimanjaro, Tanzania. Isolated gram-negative bacteria from inpatients admitted at Kilimanjaro Christian Medical Centre (KCMC) between August 2013 and August 2015 were fully genome sequenced. The prevalence of ESBL-producing gram-negative bacteria was determined based on the presence of bla_CTX-M. The odds ratio (OR) and risk factors for ESBL-producing gram-negative bacteria due to CTX-M were assessed using logistic regression models. The overall CTX-M prevalence (95% CI) was 13.6% (10.1–18.1). Adjusted for other factors, the OR of CTX-M gram-negative bacteria for patients previously hospitalized was 0.26 (0.08–0.88), p = 0.031; the OR for patients currently on antibiotics was 4.02 (1.29–12.58), p = 0.017; the OR for patients currently on ceftriaxone was 0.14 (0.04–0.46), p = 0.001; and the OR for patients with wound infections was 0.24 (0.09–0.61), p = 0.003. The prevalence of ESBL-producing gram-negative bacteria due to CTX-M in this setting is relatively low compared to other previous reports in similar settings. However, to properly stop further spread in the hospital, we recommend setting up a hospital surveillance system that takes full advantage of the available next-generation sequencing facility to routinely screen for all types of bacterial resistance genes.

Genetic Background of β-Lactamases in Enterobacteriaceae Isolates from Environmental Samples

The prevalence of β-lactamase-producing Enterobacteriaceae has increased worldwide. Although antibiotic-resistant bacteria are usually associated with hospitals, there are a growing number of reports of resistant bacteria in other environments. Concern about resistant microorganisms outside the hospital setting highlights the need to investigate mechanisms of antibiotic resistance in isolates collected from the environment. The present study evaluated the resistance mechanism to β-lactam antibiotics in 40 isolates from hospital sewage and surface water from the Dilúvio Stream, Porto Alegre City, Southern Brazil. The multiplex PCR technique was used to detect several resistance genes of β-lactamases: extended-spectrum β-lactamases (ESBLs), carbapenemases, and β-lactamase AmpC. After genes, detection amplicons were sequenced to confirm their identification. The clonal relationship was established by DNA macrorestriction using the XbaI enzyme, followed by pulsed-field gel electrophoresis (PFGE). The results indicated that resistance genes were present in 85% of the isolates. The most prevalent genes encoded narrow-spectrum β-lactamase, such as TEM-1 and SHV-1 with 70% of the strains, followed by carbapenemase KPC and GES (45%), ESBL types SHV-5 and CTX-M-8 (27.5%), and AmpC (ACT-1/MIR-1) (2.5%). Twelve isolates contained only one resistance gene, 14 contained two, and eight isolates had three resistance genes. PFGE indicated a clonal relationship among K. pneumoniae isolates. It was not possible to establish a clonal relationship between Enterobacter sp. isolates. The results highlight the potential of these resistance genes to spread in the polluted environment and to present a health risk to communities. This report is the first description of these resistance genes present in environmental samples other than a hospital in the city of Porto Alegre/RS.

Prevalence of extended-spectrum beta-lactamase-producing Enterobacteriaceae isolated from blood cultures in Africa

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae have been isolated from many regions of the world. Epidemiological studies are being conducted in Europe, North America, and Asia. No study has however been conducted in Africa to determine the prevalence and distribution of ESBLs on the continent. This literature review aimed at describing the prevalence of ESBL-producing Enterobacteriaceae isolated from blood cultures, as well as the ESBL genes involved at the international level. Our focus was mainly on Africa. We conducted a literature review on PubMed. Articles related to our study field and published between 1996 and 2014 were reviewed and entirely read for most of them, while we only focused on the abstracts of some other articles. Relevant articles to our study were then carefully reviewed and included in the review. The prevalence of ESBL-producing Enterobacteriaceae differs from one country to another. The results of our literature review however indicate that class A ESBLs prevail over the other types. We took into consideration articles focusing on various types of samples to assess the prevalence of ESBL-producing Enterobacteriaceae, but information on isolates from blood cultures is limited. The worldwide prevalence of ESBL-producing Enterobacteriaceae has increased over time. Evidence of ESBL-producing Enterobacteriaceae can be found in all regions of the world. Studies conducted in Africa mainly focused on the Northern and Eastern parts of the continent, while only rare studies were carried out in the rest of the continent.

Meta-analysis of proportion estimates of Extended-Spectrum-Beta-Lactamase-producing Enterobacteriaceae in East Africa hospitals

Background

A high proportion of Extended-Spectrum-Beta-Lactamase (ESBL) producing Enterobacteriaceae is causing common infections in all regions of the world. The burden of antibiotic resistance due to ESBL in East Africa is large but information is scarce and thus it is unclear how big the problem really is. To gain insight into the magnitude and molecular epidemiology of ESBL-producing Enterobacteriaceae in East Africa a literature search was performed in PubMed on 31 July 2015 to retrieve articles with relevant information on ESBL.

Methods and results

Meta-analysis was performed to determine overall proportion estimate of ESBL-producing Enterobacteriaceae. A total of 4076 bacterial isolates were included in the analysis. The overall pooled proportion of ESBL-producing Enterobacteriaceae among included surveys done in East African hospitals was found to be 0.42 (95 % CI: 0.34–0.50). Heterogeneity (I²) between countries’ proportions in ESBL was significantly high (96.95 % and p < 0.001). The frequently detected genes encoding ESBL were CTX-M, TEM, SHV and OXA while the most infrequent reported genes were KPC and NDM.

Conclusion

The available studies show a very wide variation in resistance due to ESBL between countries. This highlights a need for active surveillance systems which can help understand the actual epidemiology of ESBL, aid in formulating national or regional guidelines for proper screening of ESBL, and support developing standardized approaches for managing patients colonized with ESBL.

Electronic supplementary material

The online version of this article (doi:10.1186/s13756-016-0117-4) contains supplementary material, which is available to authorized users.

Fecal Colonization With Extended-spectrum Beta-lactamase-Producing Enterobacteriaceae and Risk Factors Among Healthy Individuals: A Systematic Review and Metaanalysis

BACKGROUND

Gut colonization is a risk factor for infections with extended-spectrum beta-lactamase (ESBL)-producing organisms. We aimed to determine the ESBL class A reservoir among healthy individuals.

METHODS

We searched PubMed and EMBASE (through 10 July 2015) looking for studies that contained data for fecal colonization with ESBL class A bacteria among healthy individuals for each World Health Organization-defined region. Distribution of isolates among cefotaximase (CTX-M), sulfhydryl variable, and temoneira enzymes and data on previous antibiotic use, international travel, previous hospitalization, and animal contacts were extracted.

RESULTS

Sixty-six of 17 479 studies on 28 909 healthy individuals were included. The pooled prevalence of ESBL class A colonization was 14% (95% confidence interval [CI], 9, 20), with an increasing trend of 5.38% annually (P = .003). The pooled prevalence was higher in Asia and Africa (ranging from 46%, 95% CI, 29, 63 to 15%, 95% CI, 4, 31) and lower but still significant in central (3%, 95% CI, 1, 5), northern (4%, 95% CI, 2, 6), and southern Europe (6%, 95% CI, 1, 12) and the Americas (2%, 95% CI, 0, 5). CTX-Ms were the prevalent ESBL enzyme (69%). Antibiotic use for the prior 4 or 12 months was associated with a high colonization risk (risk ratio [RR] = 1.63; 95% CI, 1.19, 2.24 and RR = 1.58; 95% CI, 1.16, 2.16, respectively). International travel was also correlated with ESBL colonization [(RR = 4.06, (95% CI, 1.33, 12.41)].

CONCLUSIONS

The ESBL colonization rate among healthy individuals is significant worldwide. This should be taken into consideration in infection control and antibiotic management decisions.

Predictors of blaCTX-M-15 in varieties of Escherichia coli genotypes from humans in community settings in Mwanza, Tanzania

BACKGROUND

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae commonly cause infections worldwide. Bla CTX-M-15 has been commonly detected in hospital isolates in Mwanza, Tanzania. Little is known regarding the faecal carriage of ESBL isolates and bla CTX-M-15 allele among humans in the community in developing countries.

METHODS

A cross-sectional study involving 334 humans from the community settings in Mwanza City was conducted between June and September 2014. Stool specimens were collected and processed to detect ESBL producing enterobacteriaceae. ESBL isolates were confirmed using disc approximation method, commercial ESBL plates and VITEK-2 system. A polymerase chain reaction and sequencing based allele typing for CTX-M ESBL genes was performed to 42 confirmed ESBL isolates followed by whole genome sequence of 25 randomly selected isolates to detect phylogenetic groups, sequence types plasmid replicon types.

RESULTS

Of 334 humans investigated, 55 (16.5 %) were found to carry ESBL-producing bacteria. Age, history of antibiotic use and history of admission were independent factors found to predict ESBL-carriage. The carriage rate of ESBL-producing Escherichia coli was significantly higher than that of Klebsiella pneumoniae (15.1 % vs. 3.8 %, p = 0.026). Of 42 ESBL isolates, 37 (88.1 %) were found to carry the bla CTX-M-15 allele. Other transferrable resistance genes were aac(6')Ib-cr, aac(3)-IIa, aac(3)-IId, aadA1, aadA5, strA, strB and qnrS1. Eight multi-locus sequence types (ST) were detected in 25 E. coli isolates subjected to genome sequencing. ST-131 was detected in 6 (24 %), ST-38 in 5 (20 %) and 5 (20 %) clonal complex - 10(ST-617, ST-44) of isolates. The pathogenic phylogenetic groups D and B2 were detected in 8/25 (32 %) and 6/25 (24 %) of isolates respectively. BlaCTX-M-15 was found to be located in multiple IncY and IncF plasmids while in 13/25(52 %) of cases it was chromosomally located.

CONCLUSION

The overlap of multi-drug resistant bacteria and diversity of the genotypes carrying CTX-M-15 in the community and hospitals requires an overall approach that addresses social behaviour and activity, rationalization of the antibiotic stewardship policy and a deeper understanding of the ecological factors that lead to persistence and spread of such alleles.

Antimicrobial susceptibility profiles of Escherichia coli and Klebsiella pneumoniae isolated from outpatients in urban and rural districts of Uganda

Background

Antimicrobial resistance is a global public health concern contributing to increased morbidity and mortality particularly in low-income countries. Studies on commensal bacteria are important as they reflect the state of antimicrobial susceptibility patterns in populations. However, susceptibility data on potentially pathogenic commensal bacteria from individuals in communities are still limited. The aim of this cross-sectional study was to determine the susceptibility profiles of Escherichia coli and Klebsiella species isolated from clients attending outpatient clinics in Kampala (urban district) and two rural districts of Uganda, Kayunga and Mpigi. Factors associated with such carriage are also reported.

Results

A total of 1448 participants were recruited into the study with 985 yielding organisms of interest from stool or urine samples (one per client). Most growth occurred from stool samples (636/985, 87 %), of which 620/636 (97 %) grew E. coli while 16 (3 %) were Klebsiella pneumoniae. Growth from urine was 349/985 (35 %) of which 310/349 (89 %) were E. coli while 39 (11 %) K. pneumoniae. High rates of antimicrobial resistance were detected among E. coli and Klebsiella isolates combined: sulphamethoxazole/trimethoprim 70 %, amoxicillin/clavulanate 36 %, chloramphenicol 20 %, ciprofloxacin 11 %, gentamicin 11 %, nitrofurantoin 4 %, ceftriaxone 3 %, piperacillin/tazobactam 27 %, cefoxitin 22 %, and cefepime 15 %. Multidrug resistance was noted in 33 % of the isolates. None of the isolates were resistant to imipenem. Overall, isolates from Kampala were more resistant to antimicrobials. Across the three districts combined, isolates producing beta-lactamase enzymes extended spectrum β-lactamase-(ESBL) and AmpC comprised 5.3 and 13.2 %, respectively. Further, medical procedures involving inoculation were independent risk factors [aOR 50.76 (1.80, 1432.90)] while residing in a rural district and use of sulphamethoxazole/trimethoprim 3 months prior to visiting the outpatient clinics were protective against carriage of multidrug resistant isolates. Furthermore, use of gentamicin was protective against AmpC producing isolates while clients attending HIV/AIDs clinics were less likely to carry such isolates. No factor was independently associated with carriage of ESBL-producing isolates.

Conclusion

Antimicrobial resistance is prevalent among E. coli and K.pneumoniae carried in the gut of clients attending outpatient clinics in Kampala and two rural districts in Uganda. This could complicate treatment options for community-acquired infections caused by the Enterobacteriaceae.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-016-2049-8) contains supplementary material, which is available to authorized users.

Fecal Carriage of Enterobacteriaceae Producing Extended-Spectrum Beta-Lactamases in Hospitalized Patients and Healthy Community Volunteers in Burkina Faso

Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) have been described worldwide, but few reports focused on Burkina Faso. To assess the prevalence of digestive carriage of such bacteria in the community and in the hospital, 214 fecal samples, 101 from healthy volunteers and 113 from hospitalized patients without digestive pathology, were collected in Bobo Dioulasso, Burkina Faso economic capital, during July and August 2014. Stool samples were screened using ESBL agar plates. Strains were identified by mass spectrometry using the Biotyper MALDI-TOF. ESBL production was confirmed with the double-disc synergy test. Susceptibility was tested using the disk diffusion method on Müller-Hinton agar. The main ESBL genes were detected using multiplex PCR and bidirectional gene sequencing. Escherichia coli phylogenetic groups were identified using a PCR-based method. During the study period, prevalence of subjects with fecal ESBL-PE was 32% (69/214), 22% among healthy volunteers and 42% among inpatients. All but two ESBL, CTX-M-15 and ESBL-PE, were mostly E. coli (78%). Among the 60 ESBL-producing E. coli strains, 26% belonged to phylogenetic group D, 23.3% to group A, 20% to group B1, 6.6% to group B2, and 3.3% to the ST131 clone. Univariate analysis showed that history of hospitalization and previous antibiotic use were risk factors associated with ESBL-PE fecal carriage. In Burkina Faso, the prevalence of both healthy subjects from the community and hospitalized patients with fecal ESBL-PE is alarmingly high. This feature should be taken into consideration by both general practitioners and hospital doctors with regard to empirical treatments of infections, notably urinary tract infections.

[Evolution of antibiotic resistance of Enterobacteriaceae isolated at the Douala General Hospital from 2005 to 2012]

Introduction

Cette étude vise à déterminer le profil de résistance aux antibiotiques des entérobactéries isolées à l'Hôpital Général de Douala (Cameroun) et analyser leur évolution dans le temps.

Méthodes

Etude rétrospective, sur une période de huit ans (2005 - 2012), portant sur l'ensemble des souches d'entérobactéries isolées chez les malades ambulatoires et hospitalisés. Les prélèvements ont été analysés au laboratoire de bactériologie de l'Hôpital Général de Douala.

Résultats

Les entérobactéries étaient les germes les plus fréquents sur l'ensemble des souches isolées. Nous avons noté une prédominance d’Escherichia coli (48,5%) et de Klebsiella pneumoniae (32,8%). Pendant la période d’étude, nous avons observé des taux de résistance élevés aux principales classes d'antibiotiques, et une augmentation entre 2005 et 2012 de 29,1% à 51,6% pour les céphalosporines de troisième génération, de 29,2% à 44% pour la ciprofloxacine. L'imipénème, l'amikacine et la fosfomycine étaient les molécules les plus actives avec respectivement 1,3%, 12,9% et 13,4% des souches d'entérobactéries résistantes.

Conclusion

L’évolution des résistances des entérobactéries aux antibiotiques est un phénomène réel dans la ville de Douala. Il expose à des difficultés de prise en charge thérapeutique des infections. Lamaitrise actuelle de ce phénomène est une véritable urgence et nécessite une implication des pouvoirs publics. Des tests spécifiques de recherche des bétalactamases à spectre élargi (BLSE) et AmpC doivent être mis en place dans nos laboratoires afin de mettre en évidence les différents phénotypes de résistances.

Extended spectrum beta-lactamase carriage state among elderly nursing home residents in Beirut

Introduction. ESBL-producing Enterobacteriaceae can cause severe infections, but they are also isolated from the stool of asymptomatic subjects. Faecal carriage of such organism is poorly understood. Methods. First phase of the study was cross-sectional with prevalence and epidemiology of ESBL faecal carriage in two nursing homes in Beirut: 57 residents in the first (NH1) and 151 residents in the second (NH2). In second phase, faecal swabs from cohort of NH1 residents were examined for carriage at six-week intervals over three-month period. Residents' charts were reviewed to assess carriage risk factors. Results. Over 3 consecutive samplings at NH1, 81% of residents were at least one-time carriers with 50% at the first round, 60.4% at the second, and 74.5% at the last one. At NH2, 68.2% of residents were carriers. Constipation (in NH1) and antibiotic intake (in NH2) were significantly associated with higher ESBL faecal carriage while the length of stay at the nursing home (in NH2) was associated with less carriage. Conclusion. Faecal carriage of ESBL-producing Enterobacteriaceae is high among nursing home patients in Beirut. The rate of carriage changes rapidly and significantly over time either with multiple factors playing a possible role like outbreak spreading, antibiotic, and health care system exposure.

High Prevalence of CTX-M Beta-Lactamases in Enterobacteriaceae from Healthy Individuals in Guangzhou, China

This study aimed to determine the prevalence of extended-spectrum beta-lactamases (ESBLs) in Enterobacteriaceae and to characterize the genetic composition of ESBL determinants among Enterobacteriaceae isolates from healthy people in Guangzhou, China. A total of 200 rectal swab samples were collected from healthy asymptomatic individuals and tested for ESBL production using ChromID ESBL agar. Phenotypic ESBL producers were screened for blaCTX-M, blaTEM, and blaSHV genes using PCR and DNA sequencing. The prevalence of ESBL-producing Enterobacteriaceae among rectal swab samples was 69.5%. All ESBL-producing isolates harbored blaCTX-M genes (n=138) except for one isolate that harbored blaSHV-2a. Eleven CTX-M ESBL genes were detected. The most predominant CTX-M-type genes were blaCTX-M-14 (n=82), followed by blaCTX-M-55 (n=19), blaCTX-M-65 (n=10), and blaCTX-M-27 (n=9). Isolates carrying blaCTX-M-38,-3,-15,-14b,-98,-121 and -123 were also identified. Molecular homology analysis of the selected isolates was performed by phylogenetic grouping and multilocus sequence typing and indicated that the predominant clone belonged to A-CC10. This study showed a high rate of CTX-M-type ESBL genes among Enterobacteriaceae isolates from healthy individuals in China.

Antibiotic resistance and genotype of beta-lactamase producing Escherichia coli in nosocomial infections in Cotonou, Benin

Background

Beta lactams are the most commonly used group of antimicrobials worldwide.

The presence of extended-spectrum lactamases (ESBL) affects significantly the treatment of infections due to multidrug resistant strains of gram-negative bacilli. The aim of this study was to characterize the beta-lactamase resistance genes in Escherichia coli isolated from nosocomial infections in Cotonou, Benin.

Methods

Escherichia coli strains were isolated from various biological samples such as urine, pus, vaginal swab, sperm, blood, spinal fluid and catheter. Isolated bacteria were submitted to eleven usual antibiotics, using disc diffusion method according to NCCLS criteria, for resistance analysis. Beta-lactamase production was determined by an acidimetric method with benzylpenicillin. Microbiological characterization of ESBL enzymes was done by double disc synergy test and the resistance genes TEM and SHV were screened by specific PCR.

Results

ESBL phenotype was detected in 29 isolates (35.5%). The most active antibiotic was imipenem (96.4% as susceptibility rate) followed by ceftriaxone (58.3%) and gentamicin (54.8%). High resistance rates were observed with amoxicillin (92.8%), ampicillin (94%) and trimethoprim/sulfamethoxazole (85.7%). The genotype TEM was predominant in ESBL and non ESBL isolates with respectively 72.4% and 80%. SHV-type beta-lactamase genes occurred in 24.1% ESBL strains and in 18.1% of non ESBL isolates.

Conclusion

This study revealed the presence of ESBL producing Eschericiha coli in Cotonou. It demonstrated also high resistance rate to antibiotics commonly used for infections treatment. Continuous monitoring and judicious antibiotic usage are required.

Low rates of antimicrobial-resistant Enterobacteriaceae in wildlife in Taï National Park, Côte d'Ivoire, surrounded by villages with high prevalence of multiresistant ESBL-producing Escherichia coli in people and domestic animals

Antimicrobial resistance genes can be found in all ecosystems, including those where antibiotic selective pressure has never been exerted. We investigated resistance genes in a collection of faecal samples of wildlife (non-human primates, mice), people and domestic animals (dogs, cats) in Côte d’Ivoire; in the chimpanzee research area of Taï National Park (TNP) and adjacent villages. Single bacteria isolates were collected from antibiotic-containing agar plates and subjected to molecular analysis to detect Enterobacteriaceae isolates with plasmid-mediated genes of extended-spectrum beta-lactamases (ESBLs) and plasmid-mediated quinolone resistance (PMQR). While the prevalence of ESBL-producing E. coli in the villages was 27% in people (n = 77) and 32% in dogs (n = 38), no ESBL-producer was found in wildlife of TNP (n = 75). PMQR genes, mainly represented by qnrS1, were also present in human- and dog-originating isolates from the villages (36% and 42% in people and dogs, respectively), but no qnrS has been found in the park. In TNP, different variants of qnrB were detected in Citrobacter freundii isolates originating non-human primates and mice. In conclusion, ESBL and PMQR genes frequently found in humans and domestic animals in the villages were rather exceptional in wildlife living in the protected area. Although people enter the park, the strict biosecurity levels they are obliged to follow probably impede transmission of bacteria between them and wildlife.

Trends in human fecal carriage of extended-spectrum β-lactamases in the community: toward the globalization of CTX-M

In the last 10 years, extended-spectrum β-lactamase-producing enterobacteria (ESBL-E) have become one of the main challenges for antibiotic treatment of enterobacterial infections, largely because of the current CTX-M enzyme pandemic. However, most studies have focused on hospitalized patients, though today it appears that the community is strongly affected as well. We therefore decided to devote our investigation to trends in ESBL-E fecal carriage rates and comprehensively reviewed data from studies conducted on healthy populations in various parts of the world. We show that (i) community ESBL-E fecal carriage, which was unknown before the turn of the millennium, has since increased significantly everywhere, with developing countries being the most affected; (ii) intercontinental travel may have emphasized and globalized the issue; and (iii) CTX-M enzymes, especially CTX-M-15, are the dominant type of ESBL. Altogether, these results suggest that CTX-M carriage is evolving toward a global pandemic but is still insufficiently described. Only a better knowledge of its dynamics and biology will lead to further development of appropriate control measures.

Antibacterial resistance in sub-Saharan Africa: an underestimated emergency

Antibacterial resistance-associated infections are known to increase morbidity, mortality, and cost of treatment, and to potentially put others in the community at higher risk of infections. In high-income countries, where the burden of infectious diseases is relatively modest, resistance to first-line antibacterial agents is usually overcome by use of second- and third-line agents. However, in developing countries where the burden of infectious diseases is high, patients with antibacterial-resistant infections may be unable to obtain or afford effective second-line treatments. In sub-Saharan Africa (SSA), the situation is aggravated by poor hygiene, unreliable water supplies, civil conflicts, and increasing numbers of immunocompromised people, such as those with HIV, which facilitate both the evolution of resistant pathogens and their rapid spread in the community. Because of limited capacity for disease detection and surveillance, the burden of illnesses due to treatable bacterial infections, their specific etiologies, and the awareness of antibacterial resistance are less well established in most of SSA, and therefore the ability to mitigate their consequences is significantly limited.

ESBL-producing Enterobacteriaceae in Africa - a non-systematic literature review of research published 2008-2012

INTRODUCTION

Enterobacteriaceae producing extended-spectrum beta-lactamases (ESBL) has been found all over the world, and risk factors for acquiring these bacteria involve hospital care and antibiotic treatment. Surveillance studies are present in Europe, North America, and Asia, but there is no summarizing research published on the situation in Africa.

AIM

This review aims to describe the prevalence of ESBL-producing Enterobacteriaceae in hospital and community settings in Africa and the ESBL genes involved.

METHOD

A non-systematic literature search was performed in PubMed. All articles published between 2008 and 2012 were screened and read in full text. Relevant articles were assessed for quality of evidence and included in the review. Articles were divided into regional areas in Africa and tabulated.

RESULTS

ESBL-producing Enterobacteriaceae in hospitalized patients and in communities varies largely between countries and specimens but is common in Africa. ESBLs (class A and D) and plasmid-encoded AmpC (pAmpC) were regularly found, but carbapenemases were also present.

CONCLUSION

ESBL-producing Enterobacteriaceae in hospital and community settings in Africa is common. Surveillance of antimicrobial resistance needs to be implemented in Africa to tailor interventions targeted at stopping the dissemination of ESBL-producing Enterobacteriaceae.

Prevalence and spread of extended-spectrum β-lactamase-producing Enterobacteriaceae in Ngaoundere, Cameroon

During April 2010 and June 2010, 334 Enterobacteriaceae isolates from 590 participants (outpatients, inpatients, inpatient carers, hospital workers and members of their households) were collected from faecal samples. Based on β-lactamase pattern, origin of strains and the relationship between participants, 44 isolates of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae were selected from 44 participants (in Ngaoundere Protestant Hospital and Ngaoundere Regional Hospital, Cameroon). To determine the relatedness of bacterial strains, these isolates were fingerprinted using the automated, repetitive-sequenced-based PCR-based DiversiLab system. Subsequently, E. coli isolates that had undergone DiversiLab analysis were examined with respect to their phylogenetic group and detection of the ST131 clone to shed light on the epidemiology of these isolates in the Ngaoundere hospitals. The prevalence of faecal carriage of ESBL-producing Enterobacteriaceae among the study participants was 54.06%. According to participant groups, the prevalence of faecal carriage was also high (outpatients 45%; inpatients 67%; inpatient carers 57%; hospital workers 44%; and members of their households 46%). Analysis of the molecular epidemiology of ESBL-producing E. coli and K. pneumoniae showed a close relationship of the isolates between related and non-related individuals. In addition, DiversiLab results of E. coli identified four related isolates (4/22) from cluster III belonging to the epidemiologically important clone ST131. Our results highlight the importance of outpatients, inpatients, their carers, hospital workers and their families as reservoirs of ESBL-producing Enterobacteriaceae.

Commensal Enterobacteriaceae as reservoirs of extended-spectrum beta-lactamases, integrons, and sul genes in Portugal

Bacteria colonizing the human intestine have a relevant role in the spread of antimicrobial resistance. We investigated the faecal carriage of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in healthy humans from Portugal and analyzed the distribution of sul genes and class 1 and 2 integrons. Faecal samples (n = 113) were recovered from healthy persons (North/Centre of Portugal, 2001-2004) and plated on MacConkey agar with and without ceftazidime (1 mg/L) or cefotaxime (1 mg/L). Isolates representing different morphotypes/plate and antibiotic susceptibility patterns (n = 201) were selected. Isolates resistant to sulfonamides and/or streptomycin, gentamicin, and trimethoprim were screened (PCR and sequencing) for sul genes (sul1, sul2, sul3) and class 1 and 2 integrons. Presence of ESBLs was inferred using the double disk synergy test (DDST) and further confirmed by PCR and sequencing. ESBL producers were selected for clonal analysis, plasmid characterization and conjugation assays by standard methods. ESBL-producing isolates were found in 1.8% (2/113) of samples, corresponding to Escherichia coli of phylogroups A (n = 1) and B1 (n = 1) carrying transferable bla CTX-M-14 and the new bla TEM-153, respectively. A 80kb IncK plasmid bearing bla CTX-M-14 was found, being highly related to that widely spread among CTX-M-14 producers of humans and animals from Portugal and other European countries. sul genes were found in 88% (22/25; sul2-60%, sul1-48%, sul3-4%) of the sulfonamide resistant isolates. Class 1 integrons were more frequently found than class 2 (7%, 14/201 vs. 3%, 6/201). Interestingly, gene cassette arrangements within these platforms were identical to those commonly observed among Enterobacteriaceae from Portuguese food-producing animals, although aadA13 is here firstly described in Morganella morganii. These results reinforce the relevance of human commensal flora as reservoir of clinically relevant antibiotic resistance genes including bla ESBLs, and highly transferable genetic platforms as IncK epidemic plasmids.

CTX-M-type β-lactamases: a successful story of antibiotic resistance

Production of extended-spectrum β-lactamases (ESBLs) is the principal mechanism of resistance to oxyimino-cephalosporins evolved by members of the family Enterobacteriaceae. Among the several ESBLs emerged among clinical pathogens, the CTX-M-type enzymes have proved the most successful in terms of promiscuity and diffusion in different epidemiological settings, where they have largely replaced and outnumbered other types of ESBLs. Originated by the capture and mobilization of chromosomal β-lactamase genes of strains of Kluyvera species, the blaCTX-M genes have become associated with a variety of mobile genetic elements that have mediated rapid and efficient inter-replicon and cell-to-cell dissemination involving highly successful enterobacterial lineages (e.g. Escherichia coli ST131 and ST405, or Klebsiella pneumoniae CC11 and ST147) to yield high-risk multiresistant clones that have spread on a global scale. The CTX-Mβ-lactamase lineage exhibits a striking plasticity, with a large number of allelic variants belonging in several sublineages, which can be associated with functional heterogeneity of clinical relevance. This review article provides an update on CTX-M-type ESBLs, with focus on structural and functional diversity, epidemiology and clinical significance.

Early diagnosis of resistant pathogens: how can it improve antimicrobial treatment?

Infections with organisms that are resistant to various anti-microbial agents pose a serious challenge to effective management of infections. Resistance to antimicrobial agents, which may be intrinsic or acquired, has been noted in a wide variety of microorganisms causing human infections. These include resistance to antiviral agents in HIV, HBV, CMV and influenza virus, anti-parasitic agents in Plasmodium falciparum, anti-fungal agents in certain Candida species and MDR (multidrug-resistant) tuberculosis. It is however, the problem of multidrug-resistant bacterial infections (caused by MRSA, VRE, ESBL/AmpC/metallo-β lactamase producers and colistin-resistant Gram-negative bacilli) that has become a cause of major concern in clinical settings. Infections with these organisms can increase morbidity, mortality, increase the cost of therapy and increase the duration of hospitalization. The objective of this article is to review the question how early diagnosis of these infections, affects the overall management of infected or colonized patients, with regard to antimicrobial therapy.

Fecal carriage of ESBL-producing E. coli and K. pneumoniae in children in Guinea-Bissau: a hospital-based cross-sectional study

Background

In recent years, the world has seen a surge in extended-spectrum β-lactamase (ESBL)-producing bacteria. However, data on the dissemination of ESBL-producing Enterobacteriaceae in the community from systematically enrolled study subjects in Africa remains limited. To determine the prevalence, phenotypic resistance patterns and genetic characteristics of ESBL-producing E. coli and K. pneumoniae in fecal carriage and to analyze associated risk factors in children attending a pediatric emergency department in Guinea-Bissau.

Methodology/Principal Findings

From June to September 2010, children <5 years of age with fever or tachycardia attending a pediatric emergency ward during the day was screened for ESBL carriage in feces. Socio-demographic and health seeking behavior data was collected. Antibiotic susceptibility was tested with VITEK2 and EUCAST disk diffusion method, molecular characterization of ESBL-encoding genes was performed with multiplex PCR and clonal relatedness was established by automated rep-PCR. Of 408 enrolled children 133 (32.6%) were ESBL carriers. In total, 83 E. coli and 91 K. pneumoniae ESBL-producing isolates were obtained. Nearly all isolates were multidrug-resistant. Co-resistance to ciprofloxacin, trimethoprim-sulfamethoxazole and aminoglycosides was common. Of the isolates, 38.5% were co-resistant to these classes plus extended-spectrum cephalosporins, which infers resistance to all easily available antibiotic agents for treatment of gram-negative sepsis in Guinea-Bissau. The predominant resistance-encoding gene subgroup was bla_CTX-M-1 and epidemiologic typing showed that the bacterial ESBL population was highly diverse both for E. coli and K. pneumoniae. Bed sharing with another child <5 years of age was a risk factor for ESBL carriage, indicating crowding as a potential risk factor for transmission of ESBL-producing bacteria.

Conclusions/Significance

Prevalence of ESBL-producing bacteria in this population was high and clonally diverse. This is alarming considering the limited diagnostic and treatment possibilities in Guinea-Bissau and other resource-poor countries.