Antimicrobial resistance in pathogens causing nosocomial infections in surgery and intensive care units of two hospitals in Antananarivo, Madagascar

Comprehensive analysis of antimicrobial resistance in the Southwest Indian Ocean: focus on WHO critical and high priority pathogens

The spread of antimicrobial resistance (AMR) is a major global concern, and the islands of the Southwest Indian Ocean (SWIO) are not exempt from this phenomenon. As strategic crossroads between Southern Africa and the Indian subcontinent, these islands are constantly threatened by the importation of multidrug-resistant bacteria from these regions. In this systematic review, our aim was to assess the epidemiological situation of AMR in humans in the SWIO islands, focusing on bacterial species listed as priority by the World Health Organization. Specifically, we examined Enterobacterales, Acinetobacter spp., Pseudomonas spp. resistant to carbapenems, and Enterococcus spp. resistant to vancomycin. Our main objectives were to map the distribution of these resistant bacteria in the SWIO islands and identify the genes involved in their resistance mechanisms. We conducted literature review focusing on Comoros, Madagascar, Maldives, Mauritius, Mayotte, Reunion Island, Seychelles, Sri Lanka, and Zanzibar. Our findings revealed a growing interest in the investigation of these pathogens and provided evidence of their active circulation in many of the territories investigated. However, we also identified disparities in terms of data availability between the targeted bacteria and among the different territories, emphasizing the need to strengthen collaborative efforts to establish an efficient regional surveillance network.

ESBL-Type and AmpC-Type Beta-Lactamases in Third Generation Cephalosporin-Resistant Enterobacterales Isolated from Animal Feces in Madagascar

Third generation cephalosporin-resistant (3GCR) Enterobacterales are known to be prevalent in Madagascar, with high colonization or infection rates in particular in Madagascan patients. Extended spectrum beta-lactamases (ESBLs) have been reported to be the predominant underlying resistance mechanism in human isolates. So far, little is known on antimicrobial resistance and its molecular determinants in Enterobacterales and other bacteria causing enteric colonization of Madagascan wild animals. To address this topic, swabs from 49 animal stool droppings were collected in the Madagascan Tsimanapesotsa National Park and assessed by cultural growth of bacterial microorganisms on elective media. In addition to 7 Acinetobacter spp., a total of 31 Enterobacterales growing on elective agar for Enterobacterales could be isolated and subjected to whole genome sequencing. Enterobacter spp. was the most frequently isolated genus, and AmpC-type beta-lactamases were the quantitatively dominating molecular resistance mechanism. In contrast, the blaCTX-M-15 gene, which has repeatedly been associated with 3GC-resistance in Madagascan Enterobacterales from humans, was detected in a single Escherichia coli isolate only. The identification of the fosfomycin-resistance gene fosA in a high proportion of isolates is concerning, as fosfomycin is increasingly used to treat infections caused by multidrug-resistant bacteria. In conclusion, the proof-of-principle assessment indicated a high colonization rate of resistant bacteria in stool droppings of Madagascan wild animals with a particular focus on 3GCR Enterobacterales. Future studies should confirm these preliminary results in a more systematic way and assess the molecular relationship of animal and human isolates to identify potential routes of transmission.

Emergence of Extended-Spectrum Beta-Lactamase and Carbapenemase Producing Gram Negative Non-Fermenters at Selected Hospitals of Northeast Ethiopia: A Prospective Cross-Sectional Study

Background

The emergence and spread of extended-spectrum β-lactamases (ESβLs) and carbapenemase (CP) producing gram negative non-fermenters are becoming a serious public health threat globally. Infections caused by these pathogens limit treatment options and contribute to the significant morbidity and mortality. Thus, to reduce their spread, early detection of these superbugs is very crucial. This study therefore aimed to assess the prevalence of ESβLs and CP producing gram negative non-fermenters at selected hospitals of North East Ethiopia.

Methods

A cross-sectional study was conducted from January to June 2021. Acinetobacter baumannii (A. baumannii) and Pseudomonas aeruginosa (P. aeruginosa) were identified using standard bacteriological techniques. ESβL and CP production were detected by combined disk diffusion and modified carbapenem inhibitory methods, respectively. Data were collected via face-to-face interview and patient card review. Chi-squared and Fisher's exact tests were calculated and p-value < 0.05 was considered statistically significant.

Results

A total of 384 patients participated in this study. Overall, 30 (7.8%) patients had positive culture for A. baumannii and P. aeruginosa. The prevalence of A. baumannii was 20 (5.2%) and that of P. aeruginosa was 10 (2.6%). From the overall isolates, 16 (53.3%) were ESβL and the proportion of carbapenemase production was 4 (13.3%). ESβL production was 8 (40%) in A. baumannii and 8 (80%) in P. aeruginosa isolates. ESβL production infections were significantly associated with hospitalization (p=0.004). Intravenous catheterization, hospitalization, and surgery had significant association with ESβL production (p<0.005). All isolates of A. baumannii and P. aeruginosa were MDR.

Conclusion

ESβL and carbapenemase production among A. baumannii and P. aeruginosa were high in the selected hospitals. The treatment of such resistant infectious agents should be guided by antimicrobial susceptibility test in a study setting. Thus, restricted and wise use of antibiotics is highly recommended to contain the spread of these superbugs. Hospitals should develop infection prevention guidelines to prevent the spread of resistant pathogens in hospitalized patients.

Antibiotic Resistance Genes in Lemur Gut and Soil Microbiota Along a Gradient of Anthropogenic Disturbance

The overuse of man-made antibiotics has facilitated the global propagation of antibiotic resistance genes in animals, across natural and anthropogenically disturbed environments. Although antibiotic treatment is the most well-studied route by which resistance genes can develop and spread within host-associated microbiota, resistomes also can be acquired or enriched via more indirect routes, such as via transmission between hosts or via contact with antibiotic-contaminated matter within the environment. Relatively little is known about the impacts of anthropogenic disturbance on reservoirs of resistance genes in wildlife and their environments. We therefore tested for (a) antibiotic resistance genes in primate hosts experiencing different severities and types of anthropogenic disturbance (i.e., non-wildlife animal presence, human presence, direct human contact, and antibiotic treatment), and (b) covariation between host-associated and environmental resistomes. We used shotgun metagenomic sequencing of ring-tailed lemur (Lemur catta) gut resistomes and associated soil resistomes sampled from up to 10 sites: seven in the wilderness of Madagascar and three in captivity in Madagascar or the United States. We found that, compared to wild lemurs, captive lemurs harbored greater abundances of resistance genes, but not necessarily more diverse resistomes. Abundances of resistance genes were positively correlated with our assessments of anthropogenic disturbance, a pattern that was robust across all ten lemur populations. The composition of lemur resistomes was site-specific and the types of resistance genes reflected antibiotic usage in the country of origin, such as vancomycin use in Madagascar. We found support for multiple routes of ARG enrichment (e.g., via human contact, antibiotic treatment, and environmental acquisition) that differed across lemur populations, but could result in similar degrees of enrichment. Soil resistomes varied across natural habitats in Madagascar and, at sites with greater anthropogenic disturbance, lemurs and soil resistomes covaried. As one of the broadest, single-species investigations of wildlife resistomes to date, we show that the transmission and enrichment of antibiotic resistance genes varies across environments, thereby adding to the mounting evidence that the resistance crisis extends outside of traditional clinical settings.

Type 2 diabetes mellitus and antibiotic-resistant infections: a systematic review and meta-analysis

BACKGROUND

Type 2 diabetes mellitus (T2DM) has been associated with infectious diseases; however, whether T2DM is associated with bacterial-resistant infections has not been thoroughly studied. We ascertained whether people with T2DM were more likely to experience resistant infections in comparison to T2DM-free individuals.

METHODS

Systematic review and random-effects meta-analysis. The search was conducted in Medline, Embase and Global Health. We selected observational studies in which the outcome was resistant infections (any site), and the exposure was T2DM. We studied adult subjects who could have been selected from population-based or hospital-based studies. I² was the metric of heterogeneity. We used the Newcastle-Ottawa risk of bias scale.

RESULTS

The search retrieved 3370 reports, 97 were studied in detail and 61 (449 247 subjects) were selected. Studies were mostly cross-sectional or case-control; several infection sites were studied, but mostly urinary tract and respiratory infections. The random-effects meta-analysis revealed that people with T2DM were twofold more likely to have urinary tract (OR=2.42; 95% CI 1.83 to 3.20; I² 19.1%) or respiratory (OR=2.35; 95% CI 1.49 to 3.69; I² 58.1%) resistant infections. Although evidence for other infection sites was heterogeneous, they consistently suggested that T2DM was associated with resistant infections.

CONCLUSIONS

Compelling evidence suggests that people with T2DM are more likely to experience antibiotic-resistant urinary tract and respiratory infections. The evidence for other infection sites was less conclusive but pointed to the same overall conclusion. These results could guide empirical treatment for patients with T2DM and infections.

Antibiotic-Resistant Acinetobacter baumannii in Low-Income Countries (2000-2020): Twenty-One Years and Still below the Radar, Is It Not There or Can They Not Afford to Look for It?

Acinetobacter baumannii is an emerging pathogen, and over the last three decades it has proven to be particularly difficult to treat by healthcare services. It is now regarded as a formidable infectious agent with a genetic setup for prompt development of resistance to most of the available antimicrobial agents. Yet, it is noticed that there is a gap in the literature covering this pathogen especially in countries with limited resources. In this review, we provide a comprehensive updated overview of the available data about A. baumannii, the multi-drug resistant (MDR) phenotype spread, carbapenem-resistance, and the associated genetic resistance determinants in low-income countries (LIICs) since the beginning of the 21st century. The coverage included three major databases; PubMed, Scopus, and Web of Science. Only 52 studies were found to be relevant covering only 18 out of the 29 countries included in the LIC group. Studies about two countries, Syria and Ethiopia, contributed ~40% of the studies. Overall, the survey revealed a wide spread of MDR and alarming carbapenem-resistance profiles. Yet, the total number of studies is still very low compared to those reported about countries with larger economies. Accordingly, a discussion about possible reasons and recommendations to address the issue is presented. In conclusion, our analyses indicated that the reported studies of A. baumannii in the LICs is far below the expected numbers based on the prevailing circumstances in these countries. Lack of proper surveillance systems due to inadequate financial resources could be a major contributor to these findings.

Identification and Distribution of Pathogens in a Major Tertiary Hospital of Indonesia

The nosocomial persistence of multiple drug resistance organisms constitutes a global threat. Healthcare-setting acquired infections are subject to substantial selection pressure and are frequently associated with drug resistance. As part of the microbiological surveillance of the Sanglah tertiary referral hospital in the island province of Bali, the distribution of bacterial pathogen and their relative susceptibilities were recorded over a 30 months period. This is the first such detailed study benchmarking the type and sensitivity of bacterial pathogens in a major tertiary referral hospital within Indonesia and it is hoped that it will lead to similar reports in the near future, while informing local and national antimicrobial stewardship policies.

Transmission Routes of Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae in a Neonatology Ward in Madagascar

The diffusion of extended-spectrum beta-lactamase (E-ESBL)-producing Enterobacteriaceae is a major concern worldwide, especially in low-income countries, where they may lead to therapeutic failures. In hospitals, where colonization is the highest, E-ESBL transmission is poorly understood, limiting the possibility of establishing effective control measures. We assessed E-ESBL-acquisition routes in a neonatalogy ward in Madagascar. Individuals from a neonatology ward were longitudinally followed-up (August 2014-March 2015). Newborns' family members' and health-care workers (HCWs) were stool-sampled and tested for E-ESBL colonization weekly. Several hypothetical acquisition routes of newborns-e.g. direct contact with family members and HCWs and indirect contact with other newborns through environmental contamination, colonization pressure, or transient hand carriage-were examined and compared using mathematical modeling and Bayesian inference. In our results, high E-ESBL acquisition rates were found, reaching > 70% for newborns, > 55% for family members, and > 75% for HCWs. Modeling analyses indicated transmission sources for newborn colonization to be species dependent. Health-care workers' route were selected for Klebsiella pneumoniae and Escherichia coli, with respective estimated transmission strengths of 0.05 (0.008; 0.14) and 0.008 (0.001; 0.021) ind^-1 day^-1. Indirect transmissions associated with ward prevalence, e.g. through hand carriage or environment, were selected for Enterobacter cloacae, E. coli, and K. pneumoniae (range 0.27-0.41 ind^-1 day^-1). Importantly, family members were not identified as transmission source. To conclude, E-ESBL acquisition sources are strongly species dependent. Escherichia coli and E. cloacae involve more indirect contamination, whereas K. pneumoniae also spreads through contact with colonized HCWs. These findings should help improve control measures to reduce in-hospital transmission.

Epidemiology of Early-onset Bacterial Neonatal Infections in Madagascar

BACKGROUND

Little is known about early-onset neonatal bacterial infections (EONBI) in Madagascar. Our aim was to determine their epidemiology to improve their management.

METHODS

Inborn neonates at risk for EONBI and admitted in the neonatal unit of 2 tertiary hospitals in Antananarivo, Madagascar, were included in a prospective study from April 2012 to March 2013. Using a clinical algorithm, blood culture, gastric fluid culture and C-reactive protein dosage were performed in newborns at high risk of infection, that is, peri partum fever, prematurity <35 weeks' gestation or birth weight <2000 g, or presenting with clinical signs of infection. EONBI was defined as a bacteremia occurring within the first week of life.

RESULTS

Among 307 neonates, 75 (24.4%) had an EONBI caused by 1 (n = 59) or 2 (n = 16) bacteria (91 isolates). Gram-negative bacteria were predominant (n = 62, 82.7%), including Enterobacter cloacae (n = 26), Klebsiella pneumoniae (n = 14), Escherichia coli (n = 7) and Proteus mirabilis (n = 2). Group B Streptococcus, Acinetobacter baumanii and Enterococcus sp. represented 3.6%, 8.2% and 12.1% of the isolates, respectively. All E. cloacae and 12/14 (85.7%) K. pneumoniae were extended-spectrum β-lactamase producers. At all, 41/91 (45.1%) bacteria were multidrug-resistant (MDR) and 34/75 (45.3%) newborns had an EONBI caused by an MDR bacteria. Neonatal asphyxia was the only factor associated with multidrug resistance (odds ratio: 4.52; CI: 1.20-16.94; P = 0.025). The EONBI-related mortality (n = 20/75, 26.7%) rose up to 38.2% (n = 13/34) in case of MDR bacteria.

CONCLUSIONS

The epidemiology of EONBIs in Madagascar is comparable to that found in many low-income countries. Prevention, including improvement of hygiene during resuscitation for neonatal asphyxia, is likely to be more effective in reducing EONBI-related morbidity and mortality than using new antibiotics to counter resistance.

Multidrug-Resistant Gram-Negative Bacilli: A Retrospective Study of Trends in a Tertiary Healthcare Unit

Background and objective: Bacterial multidrug resistance is particularly common in Gram-negative bacilli (GNB), with important clinical consequences regarding their spread and treatment options. The aim of this study was to investigate the trend of multidrug-resistant GNB (MDR-GNB) in high-risk hospital departments, between 2000–2015, in intervals of five years, with the intention of improving antibiotic therapy policies and optimising preventive and control practices. Materials and methods: This is an observational, retrospective study performed in three departments of the most important tertiary healthcare unit in the southwestern part of Romania: the Intensive Care Unit (ICU), the General Surgery Department (GSD), and the Nutrition and Metabolic Diseases Department (NMDD). MDR was defined as acquired resistance to at least one agent in three or more antimicrobial categories. Trends over time were determined by the Cochran–Armitage trend test and linear regression. Results: During the study period, a total of 2531 strains of MDR-GNB were isolated in 1999 patients: 9.20% in 2000, 18.61% in 2005, 37.02% in 2010, and 35.17% in 2015. The most significant increasing trend was recorded in the ICU (gradient = 7.63, R² = 0.842, p < 0.001). The most common MDR-GNB in the ICU was isolated from bronchoalveolar aspiration samples. Concerning the proportion of different species, most of the changes were recorded in the ICU, where a statistically significant increasing trend was observed for Proteus mirabilis (gradient = 2.62, R² = 0.558, p < 0.001) and Acinetobacter baumannii (gradient = 2.25, R² = 0.491, p < 0.001). Analysis of the incidence of the main resistance phenotypes proportion identified a statistically significant increase in carbapenem resistance in the ICU (Gradient = 8.27, R² = 0.866, p < 0.001), and an increased proportion of aminoglycoside-resistant strains in all three departments, but more importantly in the ICU and GSD. Conclusion: A statistically significant increasing trend was observed in all three departments; the most significant one was recorded in the ICU, where after 2010, carbapenem-resistant strains were isolated.

Review of Antibiotic Resistance in the Indian Ocean Commission: A Human and Animal Health Issue

Antimicrobial resistance (AMR) is a major threat to human, animal health, and environment worldwide. For human, transmission occurred through a variety of routes both in health-care settings and community. In animals, AMR was reported in livestock, pets, and wildlife; transmission of AMR can be zoonotic with the probably most important route being foodborne transmission. The Indian Ocean Commission (IOC), composed of Comoros, Madagascar, Mauritius, Reunion (France), and Seychelles recognized the surveillance of AMR in both animal and human as a main public health priority for the region. Mayotte, French overseas territory, located in Comoros archipelago, was also included in this review. This review summarized our best epidemiological knowledge regarding AMR in Indian Ocean. We documented the prevalence, and phenotypic and genotypic profiles of prone to resistance Gram-positive and Gram-negative bacteria both in animals and humans. Our review clearly pointed out extended-spectrum β-lactamase and carbapenemase-producing Enterobacteriaceae as main human and animal health issue in IOC. However, publications on AMR are scarce, particularly in Comoros, Mayotte, and Seychelles. Thus, research and surveillance priorities were recommended (i) estimating the volume of antimicrobial drugs used in livestock and human medicine in the different territories [mainly third generation cephalosporin (3GC)]; (ii) developing a “One Health” surveillance approach with epidemiological indicators as zoonotic foodborne pathogen (i.e., couple Escherichia coli resistance to 3GC/carbapenems); (iii) screening travelers with a history of hospitalization and consumption of antibiotic drug returning from at risk areas (e.g., mcr-1 transmission with China or hajj pilgrims) allowing an early warning detection of the emergence for quick control measures implementation in IOC.

Ethnobotany, phytochemistry, toxicology and pharmacological properties of Terminalia sericea Burch. ex DC. (Combretaceae) - A review

ETHNOPHARMACOLOGICAL REFERENCE

The use of medicinal plants in the treatment of infections is ancient. A wide variety of ethnotherapeutic properties and pharmacological actions has been attributed to Terminalia sericea. Studies by various groups of investigators reveal that it is a multipurpose medicinal plant used mostly in the treatment of diarrhoea, sexually transmitted infections, skin rashes, tuberculosis and other infections. The current paper is aimed at providing an overview of the ethnomedicinal uses, toxicology, pharmacology and the phytochemistry of Terminalia sericea.

MATERIALS AND METHODS

Information was retrieved using various search engines, including Pubmed, Science Direct, Google Scholar, Scielo, SciFinder and Scopus. The key words used included Terminalia sericea, secondary metabolites, phytochemistry, biological activity, pharmacology, ethnobotanical survey, medicinal uses, safety, toxicology and other related words.

RESULTS

Terminalia sericea is an important medicinal plant which possesses anti-HIV, anti-fungal, anti-bacterial, anticancer, lipolytic, wound healing, antiparasitic, anti-inflammatory and anti-oxidant activity, as the most valuable biological activities, thus lending pharmacological support to the plant's folkloric uses in indigenous medicine. Toxicologically, the extracts and isolated compounds from the plant species may have mild toxic effects. Phytochemically, the plant species possesses valuable compounds including triterpenes, alkaloids and flavonoids which may well contribute to its biological activity.

CONCLUSIONS

Terminalia sericea contains secondary metabolites which are valuable in the treatment of a variety of human infections, including community acquired infections which may be prevalent in developing countries. The degree of toxicity reported in various extracts warrants further exploration of the cytotoxicity of the plant species, both against normal human cell lines and in vivo. Moreover, the acetylcholinesterase inhibitory and anti-inflammatory effects also need to be further investigated as there are only a few reports from the literature on these aspects. There is also a need to further understand the mode of action of the extracts against various enzymes relating to inflammation. Antioxidant activity of the plant extracts against various forms of free radicals needs to be investigated. Although T. sericea is reported to be used for ethnoveterinary infections, there are no scientific reports on the anti-parasitic activity of the plant species against common animal parasites.

Prevalence of nasal colonisation by methicillin-sensitive and methicillin-resistant Staphylococcus aureus among healthcare workers and students in Madagascar

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) clones pose a significant threat to hospitalised patients because the bacteria can be transmitted by asymptomatic carriers within healthcare facilities. To date, nothing is known about the prevalence of S. aureus and MRSA among healthcare workers in Madagascar. The objective of our study was to examine the prevalence and clonal epidemiology of nasal S. aureus and MRSA among healthcare workers and non-medical University students in Antananarivo, Madagascar.

METHODS

This cross sectional study screened nasal swabs taken from students and healthcare workers for S. aureus. Multiplex PCR was performed to identify S. aureus-specific (nuc), MRSA-specific mecA and mecC genes, Panton-Valentine leukocidin (PVL) (lukF-PV), and toxic shock syndrome toxin-1 (TSST-1) specific genes in methicillin-sensitive S. aureus (MSSA) and MRSA isolates. Staphylococcus protein A gene (spa) typing was performed for all confirmed MRSA isolates. The frequency distribution of nasal S. aureus and MRSA of healthcare workers and non-medical students was compared using Pearson's χ(2) test.

RESULTS

Of 1548 nasal swabs tested, 171 (11 %) were positive for S. aureus; 20 (1.3 %) of these isolates were identified as MRSA. S. aureus was detected in 91 of 863 healthcare workers (10.4 %) and in 80 (11.8 %) of 685 students; however, 14 (1.5 %) healthcare workers carried MRSA compared with six (0.9 %) students. Nasal carriage of S. aureus and MRSA was more prevalent in women than in men, and 21 (11.7 %) S. aureus isolates were PVL-positive and 36 (21 %) were TSST-1 positive. The mecC gene was not detected in any isolates. Five different spa types were identified, with spa type t186 being the predominant MRSA clone (16/20).

CONCLUSION

The results of the present study reveal a low frequency of S. aureus and MRSA nasal carriage in both students and healthcare workers from Antananarivo, Madagascar. The predominant MRSA clone (t186) was previously described in hospitalised patients in Madagascar.

Neonatal infections with multidrug-resistant ESBL-producing E. cloacae and K. pneumoniae in Neonatal Units of two different Hospitals in Antananarivo, Madagascar

Background

We investigated the molecular mechanism of ß-lactam resistance in extended-spectrum ß-lactamase (ESBL)-producing Enterobacterial strains isolated in neonatal units of different hospitals in Anatnanarivo, Madagascar.

Methods

Bacteria were identified by standard biochemical methods, disc diffusion antibiograms and Etest. Resistance genes were sought by PCR. Strains were characterized by Rep-PCR (Diversilab), plasmid analysis and rep-typing.

Results

From April 2012 to March 2013, 29 ESBL-producing E. cloacae and 15 K. pneumoniae were isolated from blood culture (n = 32) or gastric samples (n = 12) performed at day 0 or 2 from 39/303 newborns suspected of early neonatal infection. These infants were treated with expanded spectrum cephalosporins, due to lack of carbapenems, leading to a high mortality rate (45 %). Isolates recovered were all, but 4, multidrug resistant, particularly to fluoroquinolones (FQ) except for 21 E. cloacae isolates. Isolates produced TEM-1 and CTX-M-15 ß-lactamases and their genes were located on several self-transferable plasmids of variable sizes sizes that could not be linked to a major plasmid incompatibility group. E. cloacae isolates belonged to 6 Rep-types among which two counted for 11 isolates each. The FQ resistant E. cloacae isolates belonged to one clone, whereas the FQ susceptible E. cloacae isolates belonged to four clones. The K. pneumoniae isolates belonged to 9 Rep-types among which one included five isolates.

Conclusion

This study is the first molecular characterization of ESBL-producing isolates from neonatology units in Madagascar, a country with limited epidemiological data. It revealed an important multi-clonal dissemination of CTX-M-15-producing isolates reflecting both the high community carriage and the very early nosocomial contamination of the neonates.

Identification of nasal colonization with β-lactamase-producing Enterobacteriaceae in patients, health care workers and students in Madagascar

This study assesses the nasal occurrence of β-lactamase-producing Enterobacteriaceae both in patients in a hospital department of infectious diseases at admission and in healthy Madagascan students and health care workers. Nasal swabs from 681 students, 824 health care workers, and 169 patients were obtained in Antananarivo, Madagascar, and transferred to Germany. Screening for β-lactamase (ESBL, ampC) producing Enterobacteriaceae was performed by cultural and molecular approaches, comprising Brilliance ESBL agar, E-testing, ABCD-testing, and commercial hyplex ESBL and SuperBug ID PCR. Regarding ESBL-positive strains and strains with resistance against at least three out of the four tested bactericidal antibiotic drugs, 0.3% (five out of 1541) of the students and health care workers group showed nasal colonization, whereas colonization was observed in 7.1% (12 out of 169) of the hospitalized patients at admission. No appreciably reduced detection rates after sample storage and intercontinental transport were observed. A considerable proportion of nasal colonization with cephalosporin-resistant Enterobacteriaceae was demonstrated in Madagascan hospital patients at admission, posing a risk of developing future endogenous infections. The nasal colonization of healthy individuals was negligible. Good storage and transport stability of Enterobacteriaceae will allow for future studies even in areas difficult to access.

The epidemiological transition in Antananarivo, Madagascar: an assessment based on death registers (1900-2012)

Background

Madagascar today has one of the highest life expectancies in sub-Saharan Africa, despite being among the poorest countries in the continent. There are relatively few detailed accounts of the epidemiological transition in this country due to the lack of a comprehensive death registration system at the national level. However, in Madagascar’s capital city, death registration was established around the start of the 20th century and is now considered virtually complete.

Objective

We provide an overview of trends in all-cause and cause-specific mortality in Antananarivo to document the timing and pace of the mortality decline and the changes in the cause-of-death structure.

Design

Death registers covering the period 1976–2012 were digitized and the population at risk of dying was estimated from available censuses and surveys. Trends for the period 1900–1976 were partly reconstructed from published sources.

Results

The crude death rate stagnated around 30‰ until the 1940s in Antananarivo. Mortality declined rapidly after the World War II and then resurged again in the 1980s as a result of the re-emergence of malaria and the collapse of Madagascar’s economy. Over the past 30 years, impressive gains in life expectancy have been registered thanks to the unabated decline in child mortality, despite political instability, a lasting economic crisis and the persistence of high rates of chronic malnutrition. Progress in adult survival has been more modest because reductions in infectious diseases and diseases of the respiratory system have been partly offset by increases in cardiovascular diseases, neoplasms, and other diseases, particularly at age 50 years and over.

Conclusions

The transition in Antananarivo has been protracted and largely dependent on anti-microbial and anti-parasitic medicine. The capital city now faces a double burden of communicable and non-communicable diseases. The ongoing registration of deaths in the capital generates a unique database to evaluate the performance of the health system and measure intervention impacts.

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.

Risk factors and mortality of patients with nosocomial carbapenem-resistant Acinetobacter baumannii pneumonia

BACKGROUND

Acinetobacter baumannii is characterized by strictly aerobic, gram-negative, nonmotile, nonlactose-fermenting, oxidase-negative, catalase-positive coccobacilli, and the combination of its environmental resilience and its rapid development of resistance to multiple classes of antimicrobials renders it a successful nosocomial pathogen.

OBJECTIVES

The aim of this study was to identify specific risk factors and outcome of nosocomial pneumonia because of carbapenem-resistant Acinetobacter baumannii (CRAB).

METHODS

The retrospective study, set in a 1,500-bed referral and tertiary care hospital, was conducted to analyze the clinical and microbiologic data of patients with nosocomial pneumonia because of Acinetobacter baumannii (A baumannii) from January 2006 to December 2011. Comparisons were made between patients with CRAB pneumonia and patients with carbapenem-susceptible A baumannii (CSAB) pneumonia. Only the first isolation of A baumannii was considered.

RESULTS

A total of 145 patients with CSAB pneumonia and 97 patients with CRAB pneumonia was included. Among these patients, the independent risk factors for acquiring CRAB pneumonia were Acute Physiology and Chronic Health Evaluation II (APACHE II) score (>20) at admission, systemic illnesses (chronic respiratory disease and cerebrovascular accident), presence of excess noninvasive or invasive devices (mechanical ventilation), and ever used antibiotics within 28 days (carbapenem and cefepime). The patients with CRAB pneumonia had higher mortality rate than CSAB pneumonia. Multivariate analysis showed that, among patients with A baumannii pneumonia, APACHE II score (>20) at pneumonia onset, infections with other microorganisms, and inappropriate therapy were independently associated with 28-day mortality.

CONCLUSION

Patients with CRAB pneumonia have a higher mortality rate than those with CSAB pneumonia. The nosocomial occurrence of CRAB pneumonia is strongly related to systemic illnesses, APACHE II score, mechanical ventilation, and ever used antibiotics within 28 days.

Molecular characterization of multidrug-resistant extended-spectrum β-lactamase-producing Enterobacteriaceae isolated in Antananarivo, Madagascar

Background

We investigated the molecular characteristics of multidrug-resistant, extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae isolated in community settings and in hospitals in Antananarivo, Madagascar.

Results

Forty-nine E. coli, K. pneumoniae, K. oxytoca and E. cloacae ESBL-producing isolates were studied. In antimicrobial susceptibility analyses, many of the isolates exhibited resistance to aminoglycosides, fluoroquinolones and trimethoprim-sulfamethoxazole. Gene amplification analysis and sequencing revealed that 75.5% (n=37) of the isolates harbored bla_CTX-M-15 and 38.7% (n=19) harbored bla_SHV-12. The non-ESBLs resistance genes detected were bla_TEM-1, bla_OXA-1, aac(6^′)-Ib,aac(6^′)-Ib-cr, tetA, sul-1, sul-2, qnrA, qnrB and catB-3. We found dfrA and aadA gene cassettes in the class 1 integron variable regions of the isolates, and the combination of dfrA17-aadA5 to be the most prevalent. All bla_CTX-M-15 positive isolates also contained the ISEcp1 insertion element. Conjugation and transformation experiments indicated that 70.3% of the antibiotic resistance genes resided on plasmids. Through a PCR based replicon typing method, plasmids carrying the bla_SHV-12 or bla_CTX-M-15 genes were assigned to either the IncFII replicon type or, rarely, to the HI2 replicon type. All isolates were subtyped by the rep-PCR and ERIC-PCR methods.

Phylogenetic grouping and virulence genotyping of the E. coli isolates revealed that most of them belonged to group A1. One isolate assigned to group B2 harbored bla_CTX-M-15 and five virulence genes (traT, fyuA, iutA, iha and sfa) and was related to the O25b-ST131 clone.

Conclusions

Our results highlight the dissemination of multidrug resistant Enterobacteriaceae isolates in Antananarivo. These findings underline the need for a rational use of antibiotic and for appropriate methods of screening ESBL in routine laboratories in Antananarivo.

Rectal carriage of extended-spectrum beta-lactamase-producing gram-negative bacilli in community settings in Madagascar

Background

Extended-spectrum ß-lactamase-producing Enterobacteria (ESBL-PE) emerged at the end of the 1980s, causing nosocomial outbreaks and/or hyperendemic situations in hospitals and long-term care facilities. In recent years, community-acquired infections due to ESBL-PE have spread worldwide, especially across developing countries including Madagascar.

Objectives

This study aimed to determine the prevalence and risk factors of intestinal carriage of ESBL-PE in the community of Antananarivo.

Methods

Non-hospitalized patients were recruited in three health centers in different socio economic settings. Fresh stool collected were immediately plated on Drigalski agar containing 3 mg/liter of ceftriaxone. Gram-negative bacilli species were identified and ESBL production was tested by a double disk diffusion (cefotaxime and ceftazidime +/− clavulanate) assay. Characterization of ESBLs were perfomed by PCR and direct sequencing . Molecular epidemiology was analysed by Rep-PCR and ERIC-PCR.

Results

484 patients were screened (sex ratio  = 1.03, median age 28 years). 53 ESBL-PE were isolated from 49 patients (carrier rate 10.1%). The isolates included Escherichia coli (31), Klebsiella pneumoniae (14), Enterobacter cloacae (3), Citrobacter freundii (3), Kluyvera spp. (1) and Pantoae sp.(1). In multivariate analysis, only the socioeconomic status of the head of household was independently associated with ESBL-PE carriage, poverty being the predominant risk factor.

Conclusions

The prevalence of carriage of ESBL in the community of Antananarivo is one of the highest reported worldwide. This alarming spread of resistance genes should be stopped urgently by improving hygiene and streamlining the distribution and consumption of antibiotics.

A multiple antibiotic and serum resistant oligotrophic strain, Klebsiella pneumoniae MB45 having novel dfrA30, is sensitive to ZnO QDs

Background

The aim of this study was to describe a novel trimethoprim resistance gene cassette, designated dfrA30, within a class 1 integron in a facultatively oligotrophic, multiple antibiotic and human serum resistant test strain, MB45, in a population of oligotrophic bacteria isolated from the river Mahananda; and to test the efficiency of surface bound acetate on zinc oxide quantum dots (ZnO QDs) as bactericidal agent on MB45.

Methods

Diluted Luria broth/Agar (10^-3) media was used to cultivate the oligotrophic bacteria from water sample. Multiple antibiotic resistant bacteria were selected by employing replica plate method. A rapid assay was performed to determine the sensitivity/resistance of the test strain to human serum. Variable region of class 1 integron was cloned, sequenced and the expression of gene coding for antibiotic resistance was done in Escherichia coli JM 109. Identity of culture was determined by biochemical phenotyping and 16S rRNA gene sequence analyses. A phylogenetic tree was constructed based on representative trimethoprim resistance-mediating DfrA proteins retrieved from GenBank. Growth kinetic studies for the strain MB45 were performed in presence of varied concentrations of ZnO QDs.

Results and conclusions

The facultatively oligotrophic strain, MB45, resistant to human serum and ten antibiotics trimethoprim, cotrimoxazole, ampicillin, gentamycin, netilmicin, tobramycin, chloramphenicol, cefotaxime, kanamycin and streptomycin, has been identified as a new strain of Klebsiella pneumoniae. A novel dfr gene, designated as dfrA30, found integrated in class 1 integron was responsible for resistance to trimethoprim in Klebsiella pneumoniae strain MB45. The growth of wild strain MB45 was 100% arrested at 500 mg/L concentration of ZnO QDs. To our knowledge this is the first report on application of ZnO quantum dots to kill multiple antibiotics and serum resistant K. pneumoniae strain.

High prevalence of fecal carriage of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae in a pediatric unit in Madagascar

Background

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae have spread worldwide but there are few reports on carriage in hospitals in low-income countries. ESBL-producing Enterobacteriaceae (ESBL-PE) have been increasingly isolated from nosocomial infections in Antananarivo, Madagascar.

Methods

we conducted a prevalence survey in a pediatric unit from March to April 2008 Patient rectal swabs were sampled on the first and the last day of hospitalization. Medical staff and environment were also sampled. Rectal and environmental swabs were immediately plated onto Drigalski agar supplemented with 3 mg/liter of ceftriaxon.

Results

Fecal carriage was detected in 21.2% of 244 infants on admission and 57.1% of 154 on discharge, after more than 48 hours of hospitalization (p < 0.001). The species most frequently detected on admission were Escherichia coli and Klebsiella pneumoniae (36.9%), whereas, on discharge, K. pneumoniae was the species most frequently detected (52.7%). ESBL-associated resistances were related to trimethoprim-sulfamethoxazole (91.3%), gentamicin (76.1%), ciprofloxacin (50.0%), but not to amikacin and imipenem. The increased prevalence of carriage during hospitalization was related to standard antimicrobial therapy.

Conclusion

The significant emergence of multidrug-resistant enteric pathogens in Malagasy hospitals poses a serious health threat requiring the implementation of surveillance and control measures for nosocomial infections.

Dissemination of multidrug resistant Acinetobacter baumannii in various hospitals of Antananarivo Madagascar

This study reports the dissemination of multidrug-resistant (MDR) OXA-23-producing Acinetobacter baumannii clones in hospitals in Antananarivo, Madagascar. A total of 53 carbapenem-resistant A. baumannii isolates were obtained from September 2006 to March 2009 in five hospitals. These resistant strains represent 44% of all A. baumannii isolates. The double disk synergy test was performed to screen for production of metallo-beta-lactamases. Polymerase chain reaction (PCR) and DNA sequencing were performed for the detection of bla(AmpC), bla(OXA-51),bla(OXA-23), bla(OXA-24), bla(IMP), bla(VIM). The presence of the insertion sequence ISAba1 relative to blaOXA-23 and blaOXA-51 was assessed by PCR. Isolates were typed by Rep-PCR. All the isolates were MDR and produced the OXA-23 carbapenemase, which was confirmed by sequencing. PCR analysis for AmpC and OXA-51 gave positive results for all strains studied. No isolates produced metallo-beta-lactamases. In all isolates ISAba1 laid upstream of blaOXA-23. The A. baumannii isolates were separated into two genotypes; genotype A had a higher prevalence (41 strains) than genotype B (12 strains). Genotype A was present in four hospitals, whilst genotype B had spread in two hospitals. The high frequency of MDR OXA-23-producing A. baumannii in various hospitals in Antananarivo is curious since carbapenems are not available in Madagascar, but it emphasises the need for infection control procedures and strict adherence to them to prevent the spread of these resistant organisms in Antananarivo and also the need to control the use of carbapenems in the future.