Phenotypic Detection of Extended Spectrum Beta lactamase and Carbapenemase Co-producing Clinical Isolates from Two Tertiary Hospitals in Kano, North West Nigeria

The Importance of Carbapenemase-Producing Enterobacterales in African Countries: Evolution and Current Burden

Antimicrobial resistance (AMR) is a worldwide healthcare problem. Multidrug-resistant organisms (MDROs) can spread quickly owing to their resistance mechanisms. Although colonized individuals are crucial for MDRO dissemination, colonizing microbes can lead to symptomatic infections in carriers. Carbapenemase-producing Enterobacterales (CPE) are among the most important MDROs involved in colonizations and infections with severe outcomes. This review aimed to track down the first reports of CPE in Africa, describe their dissemination throughout African countries and summarize the current status of CRE and CPE data, highlighting current knowledge and limitations of reported data. Two database queries were undertaken using Medical Subject Headings (MeSH), employing relevant keywords to identify articles that had as their topics beta-lactamases, carbapenemases and carbapenem resistance pertaining to Africa or African regions and countries. The first information on CPE could be traced back to the mid-2000s, but data for many African countries were established after 2015-2018. Information is presented chronologically for each country. Although no clear conclusions could be drawn for some countries, it was observed that CPE infections and colonizations are present in most African countries and that carbapenem-resistance levels are rising. The most common CPE involved are Klebsiella pneumoniae and Escherichia coli, and the most prevalent carbapenemases are NDM-type and OXA-48-type enzymes. Prophylactic measures, such as screening, are required to combat this phenomenon.

Evaluation of three protocols for direct susceptibility testing for gram negative-Enterobacteriaceae from patient samples in Uganda with SMS reporting

In Uganda, the challenge of generating and timely reporting essential antimicrobial resistance (AMR) data has led to overreliance on empirical antibiotic therapy, exacerbating the AMR crisis. To address this issue, this study aimed to adapt a one-step AMR testing protocol alongside an SMS (Short Message Service) result relay system (SRRS), with the potential to reduce the turnaround time for AMR testing and result communication from 4 days or more to 1 day in Ugandan clinical microbiology laboratories. Out of the 377 samples examined, 54 isolates were obtained. Notably, E. coli (61%) and K. pneumoniae (33%) were the most frequently identified, majority testing positive for ESBL. Evaluation of three AMR testing protocols revealed varying sensitivity and specificity, with Protocol A (ChromID ESBL-based) demonstrating high sensitivity (100%) but no calculable specificity, Protocol B (ceftazidime-based) showing high sensitivity (100%) and relatively low specificity (7.1%), and Protocol C (cefotaxime-based) exhibiting high sensitivity (97.8%) but no calculable specificity. ESBL positivity strongly correlated with resistance to specific antibiotics, including cefotaxime, ampicillin, and aztreonam (100%), cefuroxime (96%), ceftriaxone (93%), and trimethoprim sulfamethoxazole (87%). The potential of integrating an SRRS underscored the crucial role this could have in enabling efficient healthcare communication in AMR management. This study underscores the substantial potential of the tested protocols for accurately detecting ESBL production in clinical samples, potentially, providing a critical foundation for predicting and reporting AMR patterns. Although considerations related to specificity warrant careful assessment before widespread clinical adoption.

Phenotypic Detection of Carbapenemase and AmpC-β-Lactamase Production among Extended Spectrum β-Lactamase (ESBL)-Producing Escherichia coli and Klebsiella spp. Isolated from Clinical Specimens

Introduction: Data on antimicrobial resistance (AMR) are sparse across numerous African countries, as microbiological analyses are not routinely conducted and surveillance data are not collected. Accordingly, clinical samples are not routinely tested for carbapenem-resistant bacteria and, therefore, the general understanding of their prevalence in the region remains limited. Methods: Between January 2020 and June 2022, we collected extended spectrum β-lactamase (ESBL)-producing Enterobacterales (ESBL-PE) isolates from five hospitals in Burkina Faso. After an initial culture on ESBL-selective media, the species were identified using API20E and isolates were tested against 13 antimicrobial agents using the disc diffusion method on Mueller-Hinton (MH) agar. ESBL production was confirmed via a double-disc synergy test. Production of carbapenemases and AmpC-β-lactamases and phenotypic co-resistance were determined. Results: Among the 473 ESBL-PE, 356 were ESBL-E. coli (ESBL-Ec) and 117 were Klebsiella spp. (ESBL-K). Of these isolates, 5.3% were carbapenemase and 5.3% were AmpC-β-lactamase-positive. Three types of carbapenemases were identified: 19 NDM, 3 OXA-48-like and 1 VIM. Two isolates produced both NDM and OXA-48-like carbapenemases. Carbapenemase producers were detected at all levels of healthcare. Co-resistance rates were up to 85% for aminoglycosides, 90% for sulfonamides, 95% for fluoroquinolones and 25% for chloramphenicol. Fosfomycin resistance was 6% for ESBL-Ec and 49% for ESBL-K (49%). Conclusions: Some of the ESBL-Ec and ESBL-K co-produced carbapenemases and/or AmpC-β-lactamases at all healthcare levels and in various sample types with high co-resistance rates to non-betalactams. Carbapenem resistance is no longer rare, calling for testing in routine diagnostics, a comprehensive resistance surveillance system and infection control within healthcare.

Detection of clinically relevant antibiotic-resistant bacteria in shared fomites, waste water and municipal solid wastes disposed near residential areas of a Nigerian city

Studies investigating environmental hotspots of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in Nigeria are limited. This study was designed to assess various environmental sources and commonly touched surfaces as potential carriers of ARB and ARGs with implications for public health. A total of 392 samples, including sewage (36), sludge (36), diapers (20), plastics (20), water sachet polythene bags (20), food wastes (20), soil beneath dump sites (20), and frequently touched surfaces such as restroom floors (80), corridors (24), door handles (56), and room floors and walls (60), were collected and screened for the presence of resistant bacteria carrying genes such as bla KPC, bla NDM-1, bla CMY-2, bla IMP, bla OXA66 and MecA. Additionally, we employed standard techniques to detect methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii . We also evaluated the effectiveness of routine disinfection procedures in eliminating ARB from restroom floors. Our findings revealed that sewage, sludge, diapers, food wastes and restroom floors are frequently contaminated with highly and moderately resistant strains of E. coli, K. pneumoniae, P. aeruginosa and MRSA. Notably, we identified two variants of the bla OXA51-like gene (bla OXA-66 and bla OXA-180) in A. baumannii isolated from these environmental sources. Furthermore, we detected seven ESBL- K. pneumoniae , five ESBL- A. baumannii , two ESBL- E. coli and one ESBL- P. aeruginosa , all carrying one or more ARGs (bla KPC, bla NDM-1, bla CMY-2), in isolates recovered from sewage, sludge, restroom floors and plastics. It is of note that ARB persisted on restroom floors even after disinfection procedures. In conclusion, this study highlights that environmental wastes indiscriminately discarded in residential areas and shared surfaces among individuals are heavily colonized by ARB carrying ARGs of significant public health importance.

Bacterial etiology, antimicrobial resistance and factors associated with community acquired pneumonia among adult hospitalized patients in Southwest Ethiopia

Background and Objectives

Antibiotic resistance is a significant problem that restricts the options for treating bacterial pneumonia. This research aimed to determine the bacterial causes of pneumonia and antibiotic resistance among hospitalized patients in southwest Ethiopia.

Materials and Methods

We collected and analyzed 150 sputum samples from individuals with community-acquired pneumonia from April 1st to October 30th, 2019. Standard bacteriological procedures were used to identify the bacteria. Kirby Bauer's disk diffusion method was used to assess the bacteria's susceptibility patterns. Production of carbapenemase and extended-spectrum-lactamase were confirmed phenotypically. Odds ratios and the chi-square test were computed.

Results

On the whole, bacterial pathogens were verified in 50% of the sputum samples. The predominant bacterial isolates were Klebsiella species, followed by Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pneumoniae. About 77.5% of isolates were multidrug resistant. Moreover, 40.5% and 10.8% of the isolates were ESBL and carbapenemase producers, respectively. Aging, tobacco smoking, previous history of pneumonia, heart disease, and chronic respiratory disease had association with sputum culture-positivity.

Conclusion

As a result, it is important to regularly monitor the bacterial etiologies and their patterns of resistance. Additionally, sociodemographic and clinical characteristics should all be taken into account while managing patients with pneumonia empirically in this context.

Extended-Spectrum β-Lactamase and Carbapenemase-Producing Gram-Negative Bacteria and Associated Factors Among Patients Suspected of Community and Hospital-Acquired Urinary Tract Infections at Ayder Comprehensive Specialized Hospital, Tigrai, Ethiopia

Background

Little is known about bacteria that produce extended-spectrum beta-lactamases (ESBLs) and carbapenemase in patients with urinary tract infections (UTIs) in Tigrai, Ethiopia. The aim of this study was to describe the magnitude of ESBL- and carbapenemase -producing gram-negative bacteria among patients suspected of community- and hospital-acquired UTIs at a referral hospital in Tigrai, Ethiopia.

Methods

A cross-sectional study was conducted at Ayder Comprehensive Specialized hospital from January 2020 to June 2020. A 10-20 mL sample of morning mid-stream and catheter urine was collected from consenting participants. Urine samples were cultured on cysteine lactose electrolyte deficient medium and MacConkey agar, and bacteria were identified using standard microbiological protocols. The Kirby-Bauer disk diffusion method was used for antimicrobial susceptibility testing. The combination disk and modified Hodge tests were used detect ESBL and carbapenemase production, respectively. The data was entered into EPI 3.1 software and analyzed using SPSS version 21.

Results

Overall, 67 gram-negative bacteria were recovered from 64 participants. Escherichia coli was the predominant isolate (68.6%), followed by Klebsiella pneumoniae (22.4%), while ESBL production was found in both Escherichia coli and Klebsiella pneumoniae (52.2% and 86.7%, respectively). Isolates recovered from patients with hospital-acquired UTIs were more likely to produce ESBLs (AOR= 16.2; 95% CI: 2.95-89.5). Carbapenemase was produced by 4.3% of E. coli and 20% of Klebsiella pneumoniae isolates. High resistance rates were found against tetracycline (84.8%), ampicillin (78.3%), amoxicillin/clavulanic acid (58.7%) for Escherichia coli isolates and against ampicillin (93.3%), sulphamethexazole trimethoprim (93.3%), cefotaxime (86.6%), and ceftazidime (86.6%), and tetracycline (73.3%) for Klebsiella pneumoniae.

Conclusion

Most UTIs were caused by ESBL-producing bacteria, especially those that were related to healthcare. Microbiological-based therapy for patients with UTIs is essential at our study site due to high rates of ESBL and significant carbapenemase production with concomitant high rates of drug resistance to several antibiotics.

Genotypic Determination of Extended Spectrum β-Lactamases and Carbapenemase Production in Clinical Isolates of Klebsiella pneumoniae in Southwest Nigeria

INTRODUCTION

Klebsiella pneumoniae is a major pathogen implicated in healthcare-associated infections. Extended-spectrum β-lactamase (ESBL) and carbapenemase-producing K. pneumoniae isolates are a public health concern. This study investigated the existence of some ESBL and carbapenemase genes among clinical isolates of K. pneumoniae in Southwest Nigeria and additionally determined their circulating clones.

MATERIALS AND METHODS

Various clinical samples from 420 patients from seven tertiary hospitals within Southwestern Nigeria were processed between February 2018 and July 2019. These samples were cultured on blood agar and MacConkey agar, and the isolated bacteria were identified by Microbact GNB 12E. All K. pneumoniae were confirmed by polymerase chain reaction (PCR) using the 16s rRNA gene. Antibiotic susceptibility testing (AST) was done on these isolates, and the PCR was used to evaluate the common ESBL-encoding genes and carbapenem resistance genes. Genotyping was performed using multi-locus sequencing typing (MLST).

RESULTS

The overall prevalence of K. pneumoniae in Southwestern Nigeria was 30.5%. The AST revealed high resistance rates to tetracyclines (67.2%), oxacillin (61.7%), ampicillin (60.2%), ciprofloxacin (58.6%), chloramphenicol (56.3%), and lowest resistance to meropenem (43.0%). All isolates were susceptible to polymyxin B. The most prevalent ESBL gene was the TEM gene (47.7%), followed by CTX-M (43.8%), SHV (39.8%), OXA (27.3%), CTX-M-15 (19.5%), CTX-M-2 (11.1%), and CTX-M-9 (10.9%). Among the carbapenemase genes studied, the VIM gene (43.0%) was most detected, followed by OXA-48 (28.9%), IMP (22.7%), NDM (17.2%), KPC (13.3%), CMY (11.7%), and FOX (9.4%). GIM and SPM genes were not detected. MLST identified six different sequence types (STs) in this study. The most dominant ST was ST307 (50%, 5/10), while ST258, ST11, ST147, ST15, and ST321 had (10%, 1/10) each.

CONCLUSION

High antimicrobial resistance in K. pneumoniae is a clear and present danger for managing infections in Nigeria. Additionally, the dominance of a successful international ST307 clone highlights the importance of ensuring that genomic surveillance remains a priority in the hospital environment in Nigeria.

Review and analysis of the overlapping threats of carbapenem and polymyxin resistant E. coli and Klebsiella in Africa

BACKGROUND

Carbapenem-resistant Enterobacterales are among the most serious antimicrobial resistance (AMR) threats. Emerging resistance to polymyxins raises the specter of untreatable infections. These resistant organisms have spread globally but, as indicated in WHO reports, the surveillance needed to identify and track them is insufficient, particularly in less resourced countries. This study employs comprehensive search strategies with data extraction, meta-analysis and mapping to help address gaps in the understanding of the risks of carbapenem and polymyxin resistance in the nations of Africa.

METHODS

Three comprehensive Boolean searches were constructed and utilized to query scientific and medical databases as well as grey literature sources through the end of 2019. Search results were screened to exclude irrelevant results and remaining studies were examined for relevant information regarding carbapenem and/or polymyxin(s) susceptibility and/or resistance amongst E. coli and Klebsiella isolates from humans. Such data and study characteristics were extracted and coded, and the resulting data was analyzed and geographically mapped.

RESULTS

Our analysis yielded 1341 reports documenting carbapenem resistance in 40 of 54 nations. Resistance among E. coli was estimated as high (> 5%) in 3, moderate (1-5%) in 8 and low (< 1%) in 14 nations with at least 100 representative isolates from 2010 to 2019, while present in 9 others with insufficient isolates to support estimates. Carbapenem resistance was generally higher among Klebsiella: high in 10 nations, moderate in 6, low in 6, and present in 11 with insufficient isolates for estimates. While much less information was available concerning polymyxins, we found 341 reports from 33 of 54 nations, documenting resistance in 23. Resistance among E. coli was high in 2 nations, moderate in 1 and low in 6, while present in 10 with insufficient isolates for estimates. Among Klebsiella, resistance was low in 8 nations and present in 8 with insufficient isolates for estimates. The most widespread associated genotypes were, for carbapenems, bla_OXA-48, bla_NDM-1 and bla_OXA-181 and, for polymyxins, mcr-1, mgrB, and phoPQ/pmrAB. Overlapping carbapenem and polymyxin resistance was documented in 23 nations.

CONCLUSIONS

While numerous data gaps remain, these data show that significant carbapenem resistance is widespread in Africa and polymyxin resistance is also widely distributed, indicating the need to support robust AMR surveillance, antimicrobial stewardship and infection control in a manner that also addresses broader animal and environmental health dimensions.

Combating the menace of antimicrobial resistance in Africa: a review on stewardship, surveillance and diagnostic strategies

The emergence of antibiotic-resistant pathogens has threatened not only our ability to deal with common infectious diseases but also the management of life-threatening complications. Antimicrobial resistance (AMR) remains a significant threat in both industrialized and developing countries alike. In Africa, though, poor clinical care, indiscriminate antibiotic use, lack of robust AMR surveillance programs, lack of proper regulations and the burden of communicable diseases are factors aggravating the problem of AMR. In order to effectively address the challenge of AMR, antimicrobial stewardship programs, solid AMR surveillance systems to monitor the trend of resistance, as well as robust, affordable and rapid diagnostic tools which generate data that informs decision-making, have been demonstrated to be effective. However, we have identified a significant knowledge gap in the area of the application of fast and affordable diagnostic tools, surveillance, and stewardship programs in Africa. Therefore, we set out to provide up-to-date information in these areas. We discussed available hospital-based stewardship initiatives in addition to the role of governmental and non-governmental organizations. Finally, we have reviewed the application of various phenotypic and molecular AMR detection tools in both research and routine laboratory settings in Africa, deployment challenges and the efficiency of these methods.

Prevalence of extended-spectrum β-lactamases, AmpC, and carbapenemases in Proteus mirabilis clinical isolates

Background

Proteus mirabilis is an opportunistic pathogen, causing a variety of community-acquired and nosocomial illnesses. It poses a potential threat to patients via the production of β-lactamases, which decrease the efficacy of antimicrobial treatment and impair the management of its pathogenicity. Hence, this study was established to determine the prevalence of extended-spectrum β-lactamases (ESBLs), AmpC, and carbapenemases of P. mirabilis isolated from various clinical specimens.

Results

Proteus mirabilis was identified in 20.7% (58/280) of specimens. ESBL producers were present at a rate of 51.7% (30/58). All AmpC-positive isolates (n = 20) produced ESBLs as well, so 66.7% of ESBL-producing isolates coproduced AmpC enzymes. The modified Hodge test confirmed carbapenemase production in six out of seven imipenem nonsusceptible isolates. Of these, only two (5.7%) isolates were also ESBL-and AmpC-positive. Antibiotic resistance reached the highest level for cotrimoxazole (62.1%, n = 36/58 isolates) and the lowest for imipenem (12.1%, n = 7/58 isolates). The levels of multidrug-resistant (MDR) was 41.4% among the tested isolates. The bla_SHV (83.3%), bla_AmpC (80%), and bla_VIM-1 (50%) were the most detected genes in phenotypically confirmed ESBL-, AmpC-, and carbapenemase-producing isolates, respectively. Besides, more than a half of the tested P. mirabilis strains (53%) coproduced ESBLs and AmpC. Moreover, two isolates coproduced ESBLs and AmpC together with carbapenemases. Furthermore, dendrogram analysis showed great genetic divergence based on the 21 different enterobacterial repetitive intergenic consensus (ERIC) patterns (P1–P21) through the 34 β-lactamase producers. ERIC analysis distinguished clonal similarities between isolates 21 and 22 in P2 and 9 and 10 in P4, which were isolated from the same clinical source and possessed similar patterns of β-lactamase-encoding genes.

Conclusion

Hence, there is an urgent need to monitor hospitalized patients and improve healthcare in order to reduce the incidence of infection and outbreaks of infection with antibiotic-resistant Proteus.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-022-02662-3.

Prevalencia de aislamientos de Escherichia coli y Klebsiella pneumoniae productoras de betalactamasas de espectro extendido en pacientes cubanos ambulatorios con infección del tracto urinario

Introducción. Las infecciones del tracto urinario (UTI) adquiridas en la comunidad causadas por enterobacterias productoras de β-lactamasas de espectro extendido (BLEE) son un fenómeno creciente a nivel mundial. Objetivo. Determinar la prevalencia de aislamientos de Escherichia coli y Klebsiella pneumoniae productoras de BLEE obtenidos de muestras de orina de pacientes ambulatorios con ITU adquirida en la comunidad, así como los perfiles de resistencia a antibióticos asociados al fenotipo BLEE. Materiales y métodos. Estudio descriptivo retrospectivo. Se analizaron 304 aislamientos de E. coli y 34 de K. pneumoniae obtenidos de urocultivos de pacientes con ITU adquirida en la comunidad atendidos entre enero 1 de 2019 y diciembre 31 de 2020 en el Hospital Clínico-Quirúrgico Docente Aleida Fernández Chardiet, provincia Mayabeque, Cuba. Se realizó un análisis bivariado (prueba x2) para determinar diferencias en las tasas de resistencia antibiótica entre las bacterias productoras de BLEE y las no productoras. Resultados. El 16.77% (51/304) y el 17.64 % (6/34) de los aislamientos de E. coli y K. pneumoniae se clasificaron como bacterias productoras de BLEE. En el caso de los aislados de E. coli productoras de BLEE, BLEE+ciprofloxacina fue el patrón de resistencia más frecuente (22/51; 43.13%), seguido por BLEE+ciprofloxacino y amikacina (14/51; 27.45%). Además, 41.17% (21/51); fueron multirresistentes. En el caso de K. pneumoniae productoras de BLEE, predominó el patrón de resistencia BLEE + ciprofloxacino, amikacina y nitrofurantoina (2/6; 33.33%), y 50 % (3/6) fueron multirresistentes. Conclusiones. Los resultados confirman la presencia de E. coli y K. pneumoniae productoras de BLEE, con una alta prevalencia de multirresistencia en pacientes con ITU adquirida en la comunidad en el municipio de Güines, Cuba.

Detection of carbapenemases blaOXA48-blaKPC-blaNDM-blaVIM and extended-spectrum-β-lactamase blaOXA1-blaSHV-blaTEM genes in Gram-negative bacterial isolates from ICU burns patients

Background and objectives

Burn patients are highly susceptible to invasion by multidrug-resistant Gram-negative bacteria (MDR-GNB) through post-burn damage. The prevalence of MDR-GNB isolated from burns patients has increased dramatically in the last decade, representing a serious risk to patients admitted to burns units worldwide. The challenges of managing infected burns patients are exacerbated in poor resource settings. This study was designed to develop a pathway for the rapid diagnosis of multidrug-resistant (MDR) Gram-negative infections and identify the bacterial genes including bla_OXA1, bla_TEM, and bla_SHV encoding ESBLs and bla_OXA48, bla_KPC, bla_NDM, and bla_VIM encoding carbapenemases from the patient of post burns infection. 

Methods

Clinical isolates were collected (August 2017 to August 2018) from Intensive care unit (ICU) of Burn Centre. Antibiotic susceptibility testing and phenotypic detection of ESBLs and carbapenemases was performed by disk diffusion, double disk synergy test (DDST), combination disk test (CDT), and Imipenem + EDTA combined disk test (IMP + EDTA CDT). Polymerase chain reaction (PCR) detection was performed for ESBLs bla_OXA1-bla_SHV-bla_TEM and carbapenemases genes bla_OXA48-bla_KPC-bla_NDM-bla_VIM

Results

In total, of 170 Gram-negative isolates, 104 (61.2%) were confirmed as multidrug-resistant (MDR); Pseudomonas aeruginosa was found to be the most prevalent 43/104 (41.4%), followed by Klebsiella pneumoniae 17/104 (16.4%), Acinetobacter baumannii12/104 (11.5%), and 6/104 Proteus mirabilis (5.8%). All isolates (100%) were resistant to cefotaxime and ceftazidime, while the meropenem resistance was 58.7%. ESBL and carbapenemase genotypes were found to be associated with higher MAR index (0.65–0.88) and MIC (> 32 µg/ml) values P. aeruginosa was the major ESBL and carbapenemase producer as determined by phenotypic testing and PCR. bla_TEM positive isolates among ESBLs producers were predominant 81.8% (27/33), followed by 27.3% bla_OXA1 and bla_SHV, respectively. bla_VIM positive isolates among carbapenemase producers were predominant 47.7% (21/44), followed by 27.3% bla_KPC, 20.5% bla_OXA48, and 11.4% bla_NDM positive isolates.

Conclusions

The predominant organism causing burn infections was ESBL and carbapenemase-producing Pseudomonas aeruginosa. There are only limited effective antibiotics against such strains. bla_VIM and bla_TEM individually and in co-existence with bla_KPC, bla_OXA48, bla_SHV, and bla_OXA1 confer antimicrobial resistance in burns patients. Rapid detection of ESBL and carbapenemase genes will inform treatment strategies improving the outcome for post-burn patients in ICU.

Antibiotic susceptibility patterns of pathogens isolated from laboratory specimens at Livingstone Central Hospital in Zambia

BACKGROUND

Multidrug resistance (MDR) is a global problem that require multifaceted effort to curb it. This study aimed to evaluate the antibiotic susceptibility patterns of routinely isolated bacteria at Livingstone Central Hospital (LCH).

METHODS

A retrospective study was performed on all isolated organisms from patient specimens that were processed from January 2019 to December 2021. Specimens were cultured on standard media and Kirby-Bauer disc diffusion method was employed for susceptibility testing following the Clinical and Laboratory Standard Institute's recommendations.

RESULTS

A total of 765 specimens were processed and only 500 (65.4%) met the inclusion criteria. Of the 500, 291(58.2%) specimens were received from female and from the age-group 17-39 years (253, 50.6%) and 40-80 years (145, 29%) in form of blood (331, 66.2%), urine (165, 33%) and sputum (4, 0.8%). Amongst the bacterial isolates, Staphylococcus aureus (142, 28.4%) was the commonest followed by Escherichia coli (91, 18.2%), and Enterobacter agglomerans (76, 15.2%), and Klebsiella pneumoniae (43, 8.6%). The resistance pattern revealed ampicillin (93%) as the least effective drug followed by oxacillin (88%), penicillin (85.6%), co-trimoxazole (81.5%), erythromycin (71.9%), nalidixic acid (68%), and ceftazidime (60%) whereas the most effective antibiotics were imipenem (14.5%), and piperacillin/tazobactam (16.7%). The screening of methicillin resistant Staphylococcus aureus (MRSA) with cefoxitin showed 23.7% (9/38) resistance.

CONCLUSION

Increased levels of MDR strains and rising numbers of MRSA strains were detected. Therefore, re-establishing of the empiric therapy is needed for proper patient management, studies to determine the levels of extended spectrum beta lactamase- and carbapenemase-producing bacteria are warranted.

Global Prevalence and Molecular Epidemiology of mcr-Mediated Colistin Resistance in Escherichia coli Clinical Isolates: A Systematic Review

BACKGROUND AND AIM

The continuing rise in infections caused by multi-drug resistant (MDR) bacteria is one of the most serious public health issues in today's societies. Colistin is a last-resort antimicrobial medication used to treat infections caused by MDR gram-negative bacteria; therefore resistance to this antibiotic is extremely hazardous. The current study aimed to evaluate the global prevalence and distribution of colistin resistance genes among human clinical isolates of Escherichia coli (E. coli) as a systematic review.

METHODS

PubMed, Embase, and Web of Science databases were systematically searched. For further evaluation, all original English-language articles that demonstrated colistin resistance in E. coli clinical isolates published between 2000 and 2020 were examined.

RESULTS

Out of 4857 initial articles, after various stages of review and evaluation, 190 related articles were selected. More than 79 % of the publications selected in this research were published from 2014 to 2020. In Asia, Europe, America, Africa, and Oceania, the prevalence of mobilized colistin resistance (mcr) producing colistin-resistant E. coli was 66.72%, 25.48%, 5.19%, 2.27%, and 0.32 %, respectively.

CONCLUSION

The recent widespread spreading of E. coli strains harboring mcr conferring colistin resistance, especially in Asia and Europe, is concerning and needs more attention.

Co-Existence of Certain ESBLs, MBLs and Plasmid Mediated Quinolone Resistance Genes among MDR E. coli Isolated from Different Clinical Specimens in Egypt

The emergence of multi-drug resistant (MDR) strains and even pan drug resistant (PDR) strains is alarming. In this study, we studied the resistance pattern of E. coli pathogens recovered from patients with different infections in different hospitals in Minia, Egypt and the co-existence of different resistance determinants. E. coli was the most prevalent among patients suffering from urinary tract infections (62%), while they were the least isolated from eye infections (10%). High prevalence of MDR isolates was found (73%) associated with high ESBLs and MBLs production (89.4% and 64.8%, respectively). bla_TEM (80%) and bla_NDM (43%) were the most frequent ESBL and MBL, respectively. None of the isolates harbored bla_KPC and bla_OXA-48 carbapenemase like genes. Also, the fluoroquinolone modifying enzyme gene aac-(6′)-Ib-cr was detected in 25.2% of the isolates. More than one gene was found in 81% of the isolates. Azithromycin was one of the most effective antibiotics against MDR E. coli pathogens. The high MAR index of the isolates and the high prevalence of resistance genes, indicates an important public health concern and high-risk communities where antibiotics are abused.

Multidrug-Resistant and Carbapenemase-Producing Enterobacteriaceae in Addis Ababa, Ethiopia

Background

The emergence and spread of multi-drug resistant (MDR) bacteria have become a public health problem in recent years. For the last many years, carbapenem antibiotics have been used successfully to treat infections caused by MDR Enterobacteriaceae. However, recently, Enterobacteriaceae producing carbapenemases have emerged, which confer broad resistance to most β-lactam antibiotics including carbapenems. Therefore, this study is aimed at determining the magnitude of MDR and carbapenemase-producing Enterobacteriaceae (CPE) isolated from various clinical specimens in Addis Ababa, Ethiopia.

Methods

A cross-sectional study was conducted from January to April 2018. A total of 312 Enterobacteriaceae isolates were identified from various clinical specimens. The Phoenix automated system (BD Phoenix100) was used for bacterial identification and antimicrobial susceptibility testing. Potential carbapenemase producers were confirmed by the modified carbapenem inactivation test, and KPC, MBL, and OXA-48 were phenotypically characterized by the disk diffusion method. The data obtained were entered and analyzed using SPSS version 20 software. Descriptive statistics, chi square, bivariate and multivariable logistic regression analyses were performed. P value ≤ 0.05 with corresponding 95% confidence interval was considered for statistical significance.

Results

A total of 312 Enterobacteriaceae were recovered. Of these isolates, 68.6% were MDR and 2.6% were CPE with different classes including OXA-48 1.6% (5/312), MBL 0.6% (2/312), and KPC and OXA-48 0.3% (1/312). The predominant bacterial isolates were E. coli 72.4% (226/312) followed by K. pneumoniae 13.8% (43/312). The antibiotic resistance rates of CPE isolates were significantly higher than other MDRE including ampicillin (100% versus 77.6%), cefoxitin (75% versus 20.6%), and piperacillin/tazobactam (50% versus 13.1%).

Conclusion

In this study, a relatively higher prevalence of MDR was observed, and the highest resistance was recorded against ampicillin, amoxicillin with clavulanic acid, and sulfamethoxazole-trimethoprim. Detection of CPE is important for implementing appropriate antimicrobial therapy and in controlling the spread of the infection. Furthermore, continuous screening and investigations, including genotypic characterization of CPE, are required for the prevention and control of the spread of antimicrobial-resistant pathogens.

Characterization of carbapenem-resistant gram-negative bacterial isolates from Nigeria by whole genome sequencing

This study characterized the mechanisms of carbapenem resistance in gram-negative bacteria isolated from patients in Yola, Nigeria. Whole genome sequencing (WGS) was performed on 66 isolates previously identified phenotypically as carbapenem-non-susceptible. The patterns of beta-lactamase resistance genes identified were primarily species-specific. However, bla_NDM-7 and bla_CMY-4 were detected in all Escherichia coli and most Providencia rettgeri isolates; bla_NDM-7 was also detected in 1 Enterobacter cloacae. The E. coli and E. cloacae isolates also shared bla_OXA-1, while bla_OXA-10 was found in all P. rettgeri, one Pseudomonas aeruginosa and 1 E. coli. Except for Stenotrophomonas maltophilia isolates, which only contained bla_L1, most species carried multiple beta-lactamase genes, including those encoding extended-spectrum beta-lactamases, AmpC and OXA in addition to a carbapenemase gene. Carbapenemase genes were either class B or class D beta-lactamases. No carbapenemase gene was detected by WGS in 13.6% of isolates.

The Emergence of Klebsiella pneumoniae with Reduced Susceptibility Against Third Generation Cephalosporins and Carbapenems in Lagos Hospitals, Nigeria

This study investigated the prevalence of Klebsiella (K.) pneumoniae isolates among clinical samples of patients in four medical centers in Lagos, Nigeria and the burden of extended-spectrum beta-lactamases (ESBL) and carbapenem-resistant K. pneumoniae (CRKP) strains. Different samples (stool, blood, urine, wound swabs and nasal swabs) from 127 patients with suspected Gram-negative infections based on on-site performed Gram-stain from four public hospitals between March and September 2015 were analyzed. K. pneumoniae was identified in 43 (34%) patients. Resistance rates of these 43 strains according to the CLSI breakpoints were as followed: cotrimoxazole (90.7%), cefuroxime (74.4%), ofloxacin (55.8%), ceftazidime (46.5%), and cefixime (35%). Three isolates (7%) were resistant to imipenem. All isolates were susceptible to amoxicillin/clavulanic acid and nitrofurantoin. The prevalence of ESBL-producing, MDR and CRKP strains was 69.8%, 62.8%, and 7.0%, respectively. Of the ESBL-producing isolates, two K. pneumoniae isolates obtained from urine harbored both bla_SHV and bla_CTX-M-1, and a third isolate from urine harbored only the bla_CTX-M-1. This study revealed the emergence of CRKP isolates and bla_CTX-M-1 and bla_SHV co-harboring K. pneumoniae strains in Lagos hospitals. The emergence of CRKP strains is an early warning signal for carbapenem antibiotics’ prudent use with concern for their efficacies.

Extended-spectrum Beta-lactamase and AmpC beta-lactamases producing gram negative bacilli isolated from clinical specimens at International Clinical Laboratories, Addis Ababa, Ethiopia

BACKGROUND

Extended spectrum Beta-lactamases (ESBLs) and AmpC beta-lactamases (AmpC) are the common enzymes produced by gram negative bacilli, which are their main mechanisms of resistance to all generations of cephalosporins. Hence, this study aimed to determine the magnitude of ESBLs and AmpC producing gram negative bacilli (GNB) isolated from clinical specimens at International clinical Laboratories in Addis Ababa, Ethiopia.

METHODS

A cross sectional study was conducted from January to May 2018. From different clinical specimens, 338 GNB were isolated and characterized. Bacterial species identification, antimicrobial susceptibility testing and screening for ESBLs and AmpC production were performed using Phoenix automated system (BD phoenix100). ESBLs production was confirmed using a combination disc method. All Cefoxitin resistant and confirmed ESBLs producing GNB were confirmed for AmpC beta-lactamases production by AmpC confirmatory Neo-Sensitabs discs (ROSCO tablet). Data were analyzed using SPSS version 20 software.

RESULTS

E. coli 66.0% (224/338) followed by K. pneumoniae 12.1% (41/338) were GNB most frequently isolated. The overall magnitude of ESBLs producing GNB was 38.8% (131/338) and the extent of AmpC beta-lactamase producing GNB was 2.4% (8/338). Majority of ESBLs and AmpC beta-lactamases producing GNB were isolated from urine specimens 47.5% (116/338). Ampicillin (75.4%), amoxicillin with clavulanic acid (64.0%) and sulfamethoxazole-trimethoprim (55.6%) were most the antibiotics to which resistance was most commonly found. The multidrug resistance (MDR) level of GNB was 74.0% (250/338). Of ESBLs and AmpC beta-lactamases producing GNB, 99.3% were MDR (p < 0.05).

CONCLUSION

The high magnitude of ESBLs and AmpC beta-lactamases producing GNB calls the needs of strong intervention to minimize further occurrence and spread of such GNB. More importantly, the MDR level was high which suggests continuous monitoring & reviewing of antimicrobial policy in hospitals and the country at large.

The burden of extended-spectrum β-lactamase-producing Enterobacteriaceae in Nigeria: a systematic review and meta-analysis

Antibiotic resistance on account of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) has become a major public health concern in developing countries. The presence of ESBL-PE is associated with increased morbidity, mortality and healthcare costs. There is no active antimicrobial surveillance mechanism in Nigeria. The aim of this study is to determine a precise estimate of the burden of ESBL-PE in Nigeria. We employed Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and searched electronic databases for suitable studies. We derived pooled prevalence estimates using random effects models and assessed trends with meta-regression. We found 208 studies, with 38 satisfying our inclusion criteria. The overall pooled prevalence of ESBL-PE in Nigeria was 34.6% (95% CI 26.8 to 42.3%) and increased at a rate of 0.22% per year (p for trend=0.837). In summary, we found the prevalence of ESBL-PE in Nigeria to be high and recommend a robust national survey to provide a more detailed picture of the epidemiology of ESBL-PE in Nigeria.