Rectal carriage of extended-spectrum β-lactamase- and carbapenemase-producing Enterobacteriaceae among hospitalised neonates in a neonatal intensive care unit in Fez, Morocco

OBJECTIVES

The aim of this study was to investigate the faecal carriage and molecular epidemiology of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBLE) isolated from rectal samples of neonates hospitalised in a neonatal intensive care unit (NICU) of a university hospital in Fez, Morocco.

METHODS

From February-July 2013, all neonates hospitalised in the NICU were screened for ESBLE carriage at discharge. ESBLs were identified by double-disk synergy test, PCR and DNA sequencing analysis. ESBLE were analysed by pulsed-field gel electrophoresis (PFGE), and conjugation was performed by the broth mating method.

RESULTS

In this study, 169 Enterobacteriaceae were collected from 164 neonates. The prevalence of faecal carriage of ESBLE was 58.0% (98/169), predominantly Klebsiella pneumoniae (65/98; 66.3%). A high rate of multiresistance in ESBLE was noted. bla_CTX-M-1 group (78.5%) was the most frequent ESBL gene detected, and all isolates harboured the CTX-M-15 variant. The prevalence of carbapenemase-producing Enterobacteriaceae was 1.8%, and bla_OXA-48 was the only gene found in these isolates. Sequencing revealed subgroups corresponding to bla_{(CTX-M-15,TEM-1,TEM-104,SHV-1,SHV-44,SHV-49andSHV-133)} genes. Conjugation experiments showed the transferability of bla_CTX-M-15 and bla_TEM, but not bla_SHV. These genes were carried by a high-molecular-weight conjugative plasmid (ca. 125kb). PFGE profiles demonstrated high clonal dissemination of ESBL-positive strains in the NICU.

CONCLUSIONS

These results demonstrate the existence of high clonal transmission of ESBLE in a Moroccan NICU. This finding provides useful information to implement a screening policy for resistant Enterobacteriaceae among neonates hospitalised in this ward.

Genes encoding adhesion factors and biofilm formation in methicillin-resistant Staphylococcus aureus in Morocco

INTRODUCTION

Infections involving methicillin-resistant Staphylococcus aureus (MRSA) remain a serious threat to hospitalized patients worldwide. MRSA is characterized by recalcitrance to antimicrobial therapy, which is a function not only of widespread antimicrobial resistance, but also the capacity to form biofilms. The present study evaluated the presence of genes encoding adhesion factors and the biofilm-forming capacity in MRSA.

METHODOLOGY

In this study, 53 isolates of MRSA, recovered from December 2010 to May 2014 in a mother and child hospital, CHU Mohamed VI in Marrakech, Morocco, were screened for the presence of bap and ica genes associated with biofilm formation, and for bbp, cna, ebpS, eno, fib, fnbA, fnbB, clfA, and clfB genes that encode microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). The biofilm formation assay was performed in 96-well microtiter polystyrene plates. The presence of genes was determined by polymerase chain reaction (PCR).

RESULTS

An association was found between icaD gene detection and biofilm formation; 100% of the strains harbored icaD and produced biofilm. None of the isolates harbored bap or bbp. Furthermore, 96.23% isolates were positive for fnbA, 60.37% for eno, 43.39% for clfA and clfB, 11.32% for cna, 9.34% for ebpS, 5.66% for fib, and 1.89% for fnbA.

CONCLUSIONS

Our findings showed that the MRSA carriage in Marrakech children was high. The genetic variations of adhesion genes require further investigation.

Epidemiology and virulence of VIM-4 metallo-beta-lactamase-producing Pseudomonas aeruginosa isolated from burn patients in eastern Algeria

In this study, we investigated the prevalence of carbapenem-resistant Pseudomonas aeruginosa (CRPA) in burn patients from eastern Algeria, CRPA virulence factors and the molecular epidemiology of CRPA. The overall prevalence of CRPA was 48.38%. Seven (46.66%) isolates were metallo-β-lactamases (MBL) producers and contained the MBL genes blaVIM-4 (n=6) and blaVIM-2 (n=1). Risk factors for CRPA infection were urinary catheter use and intubation (p=0.008). A high percentage of virulence factors (86.6% of these isolates were able to produce protease; 73.3% of isolates has DNase; and 66.6% were haemolysin positive) was observed in CRPA isolates. Among the seven MBL-producing isolates, four had the same clonal profile. The class 1 integrons, which contained the aadA7 gene cassette, were detected in six isolates. The 16SrRNA methylase gene, rmtB, was detected in one strain. All CRPA isolates were biofilm formers. A study on the kinetics of biofilm production revealed that biofilm production increased when the concentration of imipenem or ciprofloxacin and the incubation time increased. This is the first study to report the presence of VIM-4-producing P. aeruginosa from North Africa and also of the high prevalence of CRPA isolates. Based on our study of burn unit patients, the high percentage of P. aeruginosa with virulence factors and multi-drug resistance is alarming.

Phenotypic and genotypic characterization of Streptococcus pneumoniae resistant to macrolide in Casablanca, Morocco

In Morocco, the 13-valent pneumococcal conjugate vaccine (PCV-13) was introduced in the national immunization program (NIP) in October 2010 and replaced by the PCV-10 in July 2012. The present study aimed to determine the prevalence of erythromycin-resistant Streptococcus pneumoniae (ERSP) and to analyze the phenotypic and genotypic characteristics of these isolates in Casablanca, Morocco from January 2007 to December 2014. Isolates were obtained from the Microbiology Laboratory of Ibn Rochd University Hospital Centre of Casablanca. Serogrouping was done using Pneumotest Kit and serotyping by the Quellung capsular swelling. Antibiotic susceptibility pattern was determined by disk diffusion and Etest methods. A total of 655S. pneumoniae isolates were collected from 2007 to 2014 from pediatric and adult patients. Fifty-five percent of these isolates were from invasive pneumococcal diseases. Of the 655 isolates, 92 (14%) were ERSP. Globally, the proportion of ERSP from 2007 to 2010 (before vaccination) and from 2011 to 2014 (after vaccination) were 11.6% and 17.2% (p=0.04), respectively. Of the 92 ERSP, 89%, 4% and 7% displayed constitutive MLSB (resistance to macrolide, lincosamide and streptogramin B), inducible MLSB, and M phenotype (resistance to macrolide only), respectively. ERSP genotypic analysis showed that 90.2% carried the ermB gene, 6.5% the mefE gene, and 3.3% both the genes (ermB+mefE). The most prevalent ERSP serotypes were 6B, 19F and 23F before vaccination and 19F, 6B, 6A and 23F after vaccination. Erythromycin resistance among S. pneumoniae is relatively high in Casablanca. The contribution of PCVs to the reduction in antibiotic use is encouraging but this should be accompanied by a rational use of antibiotic.

First report of VIM-2 metallo-β-lactamases producing Pseudomonas aeruginosa isolates in Morocco

The emergence and the rapid spread of Pseudomonas aeruginosa carrying carbapenemases represent a serious threat to public health due to their delicate therapy. This work was performed to establish the resistance profile and to detect carbapenemases producing in 123 P. aeruginosa isolates. Among these 55 are environmental isolates and 68 are from the two major hospitals of Meknes-Tafilalet region in Morocco. All strains were tested against 14 antipseudomonal drugs by disc diffusion method. On carbapenem resistant strains minimum inhibitory concentrations of imipenem were determined by the E-test method. The modified Hodge test and EDTA tests were used for the detection of carbapenemases and metallo-β-lactamases (MBLs), respectively. PCR and DNA sequencing were conducted to detect carbapenemase-encoding genes and the enzyme types. 12% of isolates was susceptible to all antibiotics tested and Carbapenem resistance was observed in 33 P. aeruginosa isolates, 33.3% of them were multi-drug resistant. Among carbapenem resistant strains only two (6.1%) were positive for carbapenemases and also for MBLs. In addition to their resistance to almost all β-lactams tested, the MBLs producing strains were resistant to aminoglycosides. Molecular biology techniques confirmed the phenotypic results obtained for the two strains carbapenemase producers and demonstrated that each one of them carried blaVIM-2. The present study reports the first isolation of blaVIM genes in clinical isolates of P. aeruginosa in Morocco. Such isolates represent a serious emerging threat requiring strict hygiene measures to better control their spread.

Antibiotic resistance determinants and genetic analysis of Salmonella enterica isolated from food in Morocco

Antimicrobial-resistant non-typhoidal Salmonella (NTS) are an important cause of infection in Africa, but there is a lack of information on their molecular mechanisms of resistance and epidemiology. This study contributes to fill this gap through the characterization by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), plasmid profiling and analysis of antibiotic-resistance determinants of 94 Salmonella enterica strains isolated from food in Morocco. PFGE revealed considerable heterogeneity among the strains, showing 32 pulsotypes. MLST of strains representative of the different serovars evidenced 13 sequence types (STs), three of which were newly identified (ST1694, ST1768 and ST1818) and nine not previously reported in Morocco. Thirty-four strains harbored from one to four plasmids, of IncI1 group in S. Mbandaka, IncFIIA in S. Typhimurium, IncL/M in S. Hadar and S. Blockley. For the first time in Morocco an intact Salmonella Genomic Island 1 (SGI1) carrying the resistance genes aadA2, floR, tetG, blaPSE-1 and sul1 was detected in S. Typhimurium DT104. In serovar Hadar resistance to ampicillin, tetracycline and streptomycin was associated to blaTEM-1, tetA and strA genes respectively, whereas one mutation in gyrA (Asp87Asn) and one in parC (Thr54Ser) genes conferred resistance to nalidixic acid. These findings improve the information on foodborne Salmonella in Morocco, evidencing the presence of MDR strains potentially dangerous to humans, and provide useful data for future studies.

The ocean sampling day consortium

Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits.

Epidemiology of carbapenem non-susceptible Pseudomonas aeruginosa isolates in Eastern Algeria

Background

Carbapenem resistance among Pseudomonas aeruginosa has become a serious life-threatening problem due to the limited therapeutic options. In this study, we investigated the prevalence and the molecular epidemiology of carbapenem resistant Pseudomonas aeruginosa (CRPA) isolated from three hospitals in Annaba city, Algeria.

Methods

During the study period (January, 2012 to December, 2013), all patients infected by P. aeruginosa were considered as the potential study population. Antibiotic susceptibility testing was performed as recommended by the CLSI. Screening of carbapenemase producer isolates was performed by using imipenem-EDTA double-disk synergy test and modified Hodge test. CRPA isolates were tested for the presence of genes encoding β-lactamases, plasmid mediated quinolone resistance, aminoglycoside resistance and class 1 integrons were investigated by PCR and sequencing. The clonal relatedness among CRPA isolates was analyzed by pulsed-field gel electrophoresis method. The clinical data were collected to identify risk factors for CRPA carriage of P. aeruginosa infection.

Results

The overall prevalence of CRPA was 18.75 %. The risk factors for carrying CRPA were the length of hospital stay (p = 0.04), co-infections with Staphylococcus aureus (p = 0.01), and the use of urinary catheter (p = 0.03). The in-hospital mortality rate among case patients was 13.33 % compared with 1.53 % for control patients (p = 0.09). All CRPA isolates were multidrug resistance and the most effective antibiotic against CRPA isolates was amikacin and colistin. PFGE revealed an epidemic clonal dissemination of CRPA isolates. None of CRPA isolated were found to be carbapenemase-producers. The bla_PSE-1 and aac(3)-II gene was detected in two and five strains respectively. The class1 integrons were detected in 2 isolates with the presence of aadA7 gene cassette in these integrons.

Conclusion

The endemic clonal dissemination and multi-drug resistance of CRPA isolates in our institution is highly alarming. Strict measure will be required to control the further spread of these pathogens in hospital setting.

Correlation between staphylococcal biofilm formation in vitro and potential for catheter-related infections

INTRODUCTION

The present study evaluated biofilm-forming capacity and the presence of both icaA and icaD genes among staphylococcal strains isolated from catheter-related infections and blood culture.

METHODOLOGY

Ninety staphylococcal isolates, which included 45 strains of catheter infection origin and 45 strains of blood culture origin, were tested for their ability to produce biofilm using microtiter test plates and a catheter test. The presence of icaA and icaD genes was determined by polymerase chain reaction (PCR).

RESULTS

Of the 45 strains of catheter infection origin, 22 (48.88%) formed biofilm. In comparison, only 10 (22.22%) of the 45 strains of blood culture origin formed biofilms. Similar results were obtained from both the microplate test and catheter test. In the 32 strains that were able to form biofilm, 30 were positive for icaA and icaD genes, and the remaining 2 strains were negative for both genes. Fifteen staphylococcal strains of all origins presented only the icaA locus and did not form biofilm. In 88 of 90 tested strains (97.77%), there was a positive correlation between biofilm production and presence of icaA and icaD genes, and between no biofilm production and absence of both or only one of the tested genes.

CONCLUSIONS

The ability of staphylococcal isolates to form biofilm in vitro appears to be an indication of a virulence trait that enhances the ability of isolates to cause catheter-related infections. In addition, our results indicate an important role of ica genes and phenotypic variability of biofilm production as virulence factors in staphylococcal infections.

Fecal carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae in community setting in Casablanca

BACKGROUND

The importance of community-acquired infections due to extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) has been increasingly recognized in recent years. This study aimed to determine the prevalence of intestinal carriage of ESBL-PE in the community in Casablanca, Morocco.

METHODS

During 6 months (2013), 93 fecal samples were examined for ESBL-PE. Isolates expressing an ESBL phenotype were investigated for the presence of genes encoding β-lactamases and plasmid-mediated quinolone resistance. Conjugation experiments were done to determine the mobility of ESBL genes.

RESULTS

The prevalence of fecal carriage of ESBL-PE was 4.3% (4/93; 95% CI, 0.2-8.4). Klebsiella pneumoniae (n = 2), Enterobacter cloacae (n = 2), Escherichia coli (n = 1), and Serratia odorifera (n = 1) were the ESBL-producing species. Four (66.7%) of these isolates were multidrug-resistant. The blaSHV-12 (n = 5) was the most frequent ESBL gene detected, followed by blaCTX-M-15 (n = 3).The non-ESBL gene detected was blaTEM-1 (n = 5). One isolate harbored the qnrB1 variant. RESULTS of conjugation experiments indicated that blaSHV-12 + blaTEM-1 + qnrB1 and blaCTX-M-15 + blaTEM-1 genes were co-transferred and that these genes were carried by a conjugative plasmid of high molecular weight (125 kb).

CONCLUSION

Our results show the importance of the intestinal tract as a reservoir for ESBL-PE in the community in Morocco.

Association of apolipoprotein E gene polymorphism with end-stage renal disease and hyperlipidemia in patients on long-term hemodialysis

BACKGROUND

Cardiovascular diseases (CVDs) are the leading cause of death of patients with chronic renal failure. Apolipoprotein E (apoE) plays an important role in the homeostasis of cholesterol and triglycerides.

OBJECTIVE

We aimed to investigate the possible link(s) between apoE gene polymorphism, inflammation and lipoproteins in hemodialysis patients.

METHODS

We studied 109 end-stage renal disease (ESRD) patients and 97 controls. The serum lipids, apolipoproteins, lipoprotein particles, high-sensitivity C-reactive protein (hs-CRP) and total homocysteine (t-Hcy) levels and paraoxonase (PON) activity were determined in our patients. We also analyzed apoE gene polymorphism in the patients and controls.

RESULTS

The analysis of the apoE gene demonstrated a predominance of the e3 allele in both the patients and controls, followed by the e4 and then the e2 alleles. The analysis of the apoE genotype and allele frequencies showed significantly higher e4 allele and E3E4 genotype frequencies and decreased e3 allele and E3E3 genotype frequencies in the patients compared with the controls. The e2, e4 and E3E4 carriers within the ESRD patient population presented an atherogenic lipid profile. However, there were no significant variations in the serum PON activity and the hs-CRP and t-Hcy levels between individuals with different apoE polymorphisms.

CONCLUSIONS

Our findings suggest an association between the e4 allele, E3E4 genotype and ESRD. The apoE polymorphism affects the serum lipoprotein levels, and the ESRD patients who are e4 and e2 allele carriers are more likely to present an atherogenic lipoprotein profile that may be a major factor associated with increased risk of CVD.

Staphylococcus aureus nasal carriage in hemodialysis centers of Fez, Morocco

BACKGROUND AND OBJECTIVES

Staphylococcus aureus (S. aureus) nasal carriage may be responsible for some serious infections in hemodialyzed patients. The main target of this study was to estimate the prevalence of S. aureus nasal carriage in hemodialysis outpatients and medical staff in hemodialysis centers specifically in Fez region. The second target is to identify the risks of colonization, resistance pattern of isolates and their virulence toxin genes.

PATIENTS AND METHODS

Nasal swab specimens were obtained from 143 hemodialyzed outpatients and 32 medical staff from January to June 2012. Each participant completed a short questionnaire. Nasal carriage of S. aureus was demographically related (age, gender, hemodialysis duration), comorbidity (diabetes, malignancy) and exposure to health care (dialysis staff, hospitalization). PCR (Polymerase Chain Reaction) were used on all the isolates in the research of twelve staphylococcal enterotoxins genes. Also the PCR was used to investigate on the three factors epidermal cell differentiation inhibitors; three exfoliatin toxins; two leukotoxins; the toxic shock syndrome toxin-1 and the hemolysin beta genes.

RESULTS

Nasal screening revealed 38.16%, 50% and 18.75% S. aureus carries in chronic, acute hemodialysis patients and medical staff, respectively. Only young participants were likely to be S. aureus carries (p = 0.002). But there were no gender differences between the isolate carriers and non-carriers or some comorbidity factors such as viral hepatitis B and C, HIV (Human Immunodeficiency Virus) infections, diabetes, chronic smoking, recent hospitalization or antibiotic therapy. Out of all isolates, only one (1.61%) was methicillin-resistant and Twenty-one (33.87%) had at least two virulence toxin genes.

CONCLUSIONS

Knowledge and monitoring of antibiotic resistance profile and virulence of S. aureus carriage are essential in the treatment of infections generated by this pathogen, as well as in the control of clonal dissemination and prevent the spread of S. aureus resistance.

Influence of humans on evolution and mobilization of environmental antibiotic resistome

The clinical failure of antimicrobial drugs that were previously effective in controlling infectious disease is a tragedy of increasing magnitude that gravely affects human health. This resistance by pathogens is often the endpoint of an evolutionary process that began billions of years ago in non–disease-causing microorganisms. This environmental resistome, its mobilization, and the conditions that facilitate its entry into human pathogens are at the heart of the current public health crisis in antibiotic resistance. Understanding the origins, evolution, and mechanisms of transfer of resistance elements is vital to our ability to adequately address this public health issue.

Prevalence and characterization of extended spectrum beta-lactamase-producing Enterobacter cloacae strains in Algeria

INTRODUCTION

Expended spectrum β-lactamase (ESBL)-producing Enterobacter cloacae is an important nosocomial pathogen. In this study, the prevalence and the molecular epidemiology of ESBL producing E. cloacae strains isolated from various hospitals in Annaba, Algeria were investigated.

METHODOLOGY

The study involved 63 isolates of E. cloacae obtained during 2009 at the four hospitals in Annaba. The detection of ESBL was performed using the double-disk synergy test and the combined disk test. Minimum inhibitory concentrations (MICs) were determined using the agar dilution method. The presence of bla(CTX-M), bla(SHV), bla(TEM), and bla(DHA) β-lactamase genes was evaluated by PCR, and genomic typing was determined by pulsed-field gel electrophoresis (PFGE) analysis. The clinical and microbiological data were entered into the EpiI Info database.

RESULTS

Thirty isolates (47.6%) had an ESBL phenotype. Bla(CTX-M) group1 (76%); bla(TEM) (70%) were the most prevalent, followed by bla(DHA) (16.6%) and bla(SHV) (10%). Eighteen strains expressed at least two bla genes. MICs revealed a high level of resistance to cefotaxime, ceftazidime, and cefepime. PFGE revealed an epidemic clonal dissemination of these isolates. Various risk factors associated with the occurrence of ESBL-producing E. cloacae were detected.

CONCLUSIONS

A higher frequency of ESBL-producing isolates and a diversity of β-lactamases were detected among ESBL-producing E. cloacae; these resulted from an epidemic clonal dissemination and high transference of ESBL genes between bacteria in hospital settings. Strict measures will be required to control the further spread of these pathogens in hospital settings.

The scourge of antibiotic resistance: the important role of the environment

Antibiotic resistance and associated genes are ubiquitous and ancient, with most genes that encode resistance in human pathogens having originated in bacteria from the natural environment (eg, β-lactamases and fluoroquinolones resistance genes, such as qnr). The rapid evolution and spread of "new" antibiotic resistance genes has been enhanced by modern human activity and its influence on the environmental resistome. This highlights the importance of including the role of the environmental vectors, such as bacterial genetic diversity within soil and water, in resistance risk management. We need to take more steps to decrease the spread of resistance genes in environmental bacteria into human pathogens, to decrease the spread of resistant bacteria to people and animals via foodstuffs, wastes and water, and to minimize the levels of antibiotics and antibiotic-resistant bacteria introduced into the environment. Reducing this risk must include improved management of waste containing antibiotic residues and antibiotic-resistant microorganisms.

The scourge of antibiotic resistance: the important role of the environment

Antibiotic resistance and associated genes are ubiquitous and ancient, with most genes that encode resistance in human pathogens having originated in bacteria from the natural environment (eg, β-lactamases and fluoroquinolones resistance genes, such as qnr). The rapid evolution and spread of "new" antibiotic resistance genes has been enhanced by modern human activity and its influence on the environmental resistome. This highlights the importance of including the role of the environmental vectors, such as bacterial genetic diversity within soil and water, in resistance risk management. We need to take more steps to decrease the spread of resistance genes in environmental bacteria into human pathogens, to decrease the spread of resistant bacteria to people and animals via foodstuffs, wastes and water, and to minimize the levels of antibiotics and antibiotic-resistant bacteria introduced into the environment. Reducing this risk must include improved management of waste containing antibiotic residues and antibiotic-resistant microorganisms.

Staphylococcus aureus nasal carriage in a Moroccan dialysis center and isolates characterization

Staphylococcus aureus, which has its ecological niche in the anterior nares, has been shown to cause a variety of infectious diseases mainly for patients in hemodialysis units. We performed this study to evaluate the prevalence of nasal S. aureus carriage among hemodialysis outpatients, to determine the antimicrobial susceptibility of isolates, to characterize the virulence genes, and to identify associated risk factors. Nares swab specimens were obtained from 70 outpatients on hemodialysis between March and June 2010. Samples were plated immediately onto S. aureus specific media and pattern of antibacterial sensitivity was determined using disk diffusion method. Polymerase chain reaction was used to detect nuc, mecA, and genes encoding staphylococcal toxins. Medical record of patients was explored to determine S.aureus carriage risk factors. Nasal screening identified 42.9% S. aureus carriers with only one (3.3%) methicillin-resistant S. aureus isolate. Among the methicillin-susceptible S. aureus isolates, high rate of penicillin resistance (81.8%) has been detected. The identified risk factors were male gender and age ≤ 30 years. Research of virulence factors showed a high genetic diversity among the 30 S. aureus isolates. Twenty-one (70%) of them had at least one virulence gene, of which 3.3% were Panton-Valentine leukocidin (lukS/F-PV) genes. S. aureus carriage must be screened for at regular intervals in hemodialysis patients. Setting up a bacterial surveillance system is one of the strategies to understand the epidemiology of methicillin-resistant S. aureus, to guide local antibiotic policy and prevent spread of antibiotic-resistant S. aureus.

Klebsiella pneumoniae resistant to third-generation cephalosporins in five African and two Vietnamese major towns: multiclonal population structure with two major international clonal groups, CG15 and CG258

The molecular epidemiology of third-generation cephalosporin-resistant (3GC-R) Klebsiella pneumoniae in developing countries is poorly documented. From February 2007 to March 2008, we collected 135 3GC-R K. pneumoniae isolates from seven major towns in Maghreb (Morocco), West Africa (Senegal, Côte d'Ivoire), Central Africa (Cameroon), East Africa (Madagascar) and Southeast Asia (Vietnam). Their genetic diversity, assessed by multilocus sequence typing, was high (60 sequence types), reflecting multiclonality. However, two major clonal groups, CG15 (n = 23, 17% of isolates) and CG258 (n = 18, 13%), were detected in almost all participating centres. The two major clonal groups have previously been described in other parts of the world, indicating their global spread. The high diversity of enterobacterial repetitive intergenic consensus sequence-PCR banding patterns at the local level indicates that most isolates were epidemiologically unrelated. The isolates were characterized by the presence of multiple resistance determinants, most notably the concomitant presence of the aac(6')-Ib-cr, qnr and blaCTX-M-15 genes in 61 isolates (45%) belonging to 31 sequence types. These isolates were detected across a large geographical area including Cameroon (n = 1), Vietnam (n = 4), Madagascar (n = 10), Côte d'Ivoire (n = 12), Morocco (n = 13) and Senegal (n = 21). These results have major implications for patient management and highlight a potential reservoir for resistance determinants.

Emergence of extended-spectrum beta-lactamases-producing Escherichia coli in community-acquired urinary infections in Casablanca, Morocco

INTRODUCTION

Extended-spectrum beta-lactamase- (ESBL)-producing Escherichia coli are an increasingly significant cause of community-acquired infection worldwide. The aim of this study was to assess the prevalence of ESBL-producing E. coli in a community, to analyze the relationship between strains studied, and to characterize the ESBL genes involved in this resistance.

METHODOLOGY

ESBL production was detected by the double disk synergy test. Genes encoding ESBLs (blaTEM, blaCTM, blaSHV) were identified by PCR and DNA sequencing. Conjugation experiments were performed to check the transferability of antibiotic resistance genes. Strain inter-relationships were studied by pulsed field gel electrophoresis.

RESULTS

Seven ESBL-producing E. coli were identified among the 535 E. coli isolates. Most of them expressed a CTX-M enzyme (6/7) with a predominance of CTX-M-15 (6/6). Two strains possessed TEM in combination with CTX-M-15 or SHV-5.  Plasmid content and gene transfer analysis showed that resistance genes were carried by high molecular weight conjugative plasmids. PFGE analysis showed that the strains were not clonal.

CONCLUSIONS

ESBL-producing E. coli from urinary tract infections in Casablanca belong to different clones and carry mobile beta-lactamase genes.  It is therefore essential to monitor the epidemiology of ESBLs in E. coli and related organisms locally to effectively combat resistance.

Prevalence and characterization of extended spectrum β-lactamases in Klebsiella-Enterobacter-Serratia group bacteria, in Algeria

OBJECTIVES

The authors had for aim to assess the local epidemiology, antibiotic resistance, and molecular typing of expanded spectrum betalactamase producing Klebsiella, Enterobacter, and Serratia (ESBL KES).

MATERIALS AND METHODS

Two hundred and seven strains of the KES group were isolated in the microbiology laboratory of the Annaba Ibn Rochd hospital in 2009. The antibiotic resistance (diffusion method and MIC) was tested and ESBL detection was performed as recommended by the Clinical Laboratory Standard Institute (CLSI). The characterization of genes for resistance to β-lactams (CTX-M-1, TEM, and SHV) and AmpC cephalosporinase (DHA-1) was performed by polymerase chain reaction. The epidemiological relationship among identified strains was analyzed by Pulsed Field Gel Electrophoresis (PFGE). Genetic transfers were performed by conjugation using sodium azide resistant Escherichia coli K(12)J(5) as recipient strain.

RESULTS

The overall incidence of ESBL KES was 31.4% (65/207) distributed as follows: 17.4% of Klebsiella spp., 7.2% Enterobacter spp., and 6.8% Serratia marcescens. The β-lactamase CTX-M 1 types were predominant (88%), followed by TEM (36.5%), and SHV (31.1%). Twenty-three strains expressed at least two bla genes. DHA-1 type cephalosporinase was found in 4 E. cloacae associated with CTX-M-1. Several epidemic clones were determined. Conjugation experiments showed that bla(CTX-M), bla(TEM), and bla(SHV) were carried by conjugative plasmids of high molecular weight (≥125kb).

CONCLUSIONS

This study revealed a high frequency of ESBL KES with a predominance of CTX-M-1. This high rate of ESBLs could be due to a clonal spread and the emergence of new epidemic clones.