Epidemiology and risk factors for staphylococcal urinary tract infections in the Moroccan Casablanca area

PURPOSE

This study aimed to ascertain the prevalence and risk factors for developing staphylococcal urinary tract infections (UTIs) in the Casablanca area of Morocco.

METHODS

In Casablanca, Morocco, a retrospective evaluation of 772 UTIs patients was conducted between January 2020 and December 2022. The research included two groups of patients: those with staphylococcal UTIs and those without. Sex, age, chronic illnesses, antibiotic exposure, urinary catheterization, urological surgery, and UTIs history were the risk variables assessed. We employed a logistic regression model to identify the characteristics that were predictive of staphylococcal UTIs.

RESULTS

Eight staphylococcal species were responsible for 16.84% of UTIs in 772 non-repeating individuals. Patients infected with S. saprophyticus (35.38%) were the most common, followed by those infected with S. epidermidis (24.61%), S. aureus (13.85%), and S. hemolyticus (10.78%). Multivariate logistic regression analysis revealed that male sex (95% CI: 0.261-0.563), immunosuppression and immunosuppressive treatments (95% CI: 0.0068-0.64), chronic diseases (95% CI: 0.407-0.965), previous UTIs (95% CI: 0.031-0.228), frequency of urination more than 8 times a day (95% CI:1.04-3.29), frequency of urination once or twice a day (95% CI: 1.05-2.39), and urinary catheterization (95% CI: 0.02-0.22) were the most likely predictors of staphylococcal UTIs. In addition, a larger proportion of patients with staphylococcal UTIs were made aware of the risk factors associated with staphylococcal UTIs (52.31%, χ2 = 4.82, = 0.014).

CONCLUSIONS

This is the first global study to evaluate the predictive factors for acquiring UTIs caused by staphylococci. Monitoring these factors will enable medical authorities to devise effective strategies for managing UTIs and combating antibiotic resistance.

Prevalence and antibacterial resistance patterns of uropathogenic staphylococci in Casablanca, Morocco

INTRODUCTION

The purpose of this research is to evaluate the resistance profile of uropathogenic staphylococci bacteria in Casablanca, Morocco.

METHODOLOGY

In this retrospective cross-sectional research carried out from January 2017 to December 2020, isolation and identification were carried out according to the usual techniques in medical microbiology. Staphylococcus aureus isolates were confirmed by polymerase chain reaction (PCR) amplification of the nuc gene, and the antibiogram was performed according to the guidelines of the Antibiogram Committee of the French Society of Microbiology (CA-SFM 2021). The susceptibility of uropathogenic staphylococci to vancomycin was determined with broth microdilution following the recommendations of the Clinical and Laboratory Standards Institute. The mecA gene was tested on phenotypically cefoxitin-resistant S. aureus isolates by PCR.

RESULTS

The prevalence of urinary tract infections (UTIs) was 18% (772/4374). UTIs were more common in females (n = 483, 63%) than males (n = 289, 37%). Among the Gram-positive bacteria isolated (198, 25.65%), the prevalence of staphylococci was (130/198, 65.66%). Among staphylococcal species identified, coagulase-negative staphylococci (CoNS) were more prevalent (112/130, 86.15%), and Staphylococcus saprophyticus was the most frequently isolated CoNS (46/112, 41.07%). Additionally, there were several S. aureus strains (18/130, 13.85%). Forty-four percent of S. aureus isolates (n = 8) were resistant to cefoxitin and also harboured the mecA gene. All S. aureus isolates were susceptible to linezolid, cotrimoxazole and vancomycin.

CONCLUSIONS

The prevalence and antibacterial resistance patterns of uropathogenic staphylococci in this study, with a high percentage of methicillin resistance, require careful consideration of antimicrobial therapy for staphylococcal UTIs.

Detection of Carbapenemase Encoding Gene and Resistance to Cefiderocol in Hospital and Community eXtensive Drug Resistance and Carbapenem-Resistant Pseudomonas aeruginosa Strains in Morocco

Pseudomonas aeruginosa (Pa) remains among clinically-significant Gram-negative species. The carbapenems are often the last resort for treating infections due to multidrug resistant isolates such as Pa. The carbapenems' efficacy is increasingly compromised by the emergence and the rapid spread of Pa carrying carbapenemases which represent a serious threat to public health. This study aimed to establish the resistance profile and to identify carbapenemase genes in isolates with imipenem resistant phenotypes. Among 134 Pa isolates collected both in the community (46) and hospital (88) from January 2021 to December 2021 in Morocco, 18 (8 were from the community and 10 from the hospital settings) were carbapenem resistant. The identification of these strains has been confirmed using matrix assisted laser desorption ionization-time of flight (MALDI-TOF). The antibiotic susceptibility testing against 16 antibiotics was carried out and interpreted according to the recommendations of the European Committee on Antimicrobial Susceptibility Testing (2021). The worrying antibiotics resistance profiles, which spread to cefiderocol for two isolates, were obtained for all isolates, which were eXtensive Drug Resistance showing highly resistant to all antibiotic categories tested, even to ceftolozane-tazobactam. Colistin (100% susceptible) and cefiderocol (88.88%) were the most active agents against carbapenem-resistant Pa (CRPa). Phenotypic detection by NP-CARBA and NG-CARBA tests of metallo‑β‑lactamase (MβL) production was confirmed by PCR amplification and sequencing. Three CRPa isolates coharboring blaVIM-2-blaNDM-1 (two isolates) and blaVIM-2-blaIMP-8 (one isolate) genes were detected. In this study, we describe the coexistence of these MβL genes and the cefiderocol resistance in CRPa strains in Morocco. The alarming antibiotic resistance patterns of all these CRPa isolates and their resistance genes emphasize the importance of antimicrobial susceptibility testing in the choice of antibiotics for treating Pa infections.

Evaluation of Bioremediation Potentiality of Bacillus mojavensis Isolated from Wastewater for the Elimination of Reactive Yellow 145 and Methyl Orange

Textile industry waste has become one of the largest polluters in the world. In recent years, there has been a growing awareness of the need for sustainable and eco-friendly practices for the treatment of dye-laden effluents. Overall, this study highlights the potential of bioremediation as a sustainable solution for wastewater treatment. The Bacillus mojavensis isolated from wastewater and identified using 16S rRNA degraded reactive yellow 145 and methyl orange in 36 h of incubation, this decolorization was affected by pH, temperature, dye concentration, glucose concentration, source of nitrogen, type of dye, and agitation. Our study found that the optimal conditions for total decolorization of dyes were achieved by incubating B. mojavensis at 46 °C, pH 9, with 1 g/L of glucose and 2 g/L of peptone. The azoreductase activity, FT-IR analysis, and UV-visible spectrum before and after total decolorization indicated that it was a dye degradation rather than biosorption in surface Celle. In addition, the study of phytotoxicity show the metabolites of degradation are not phytotoxic in Lens esculenta seeds. In conclusion, our results suggest the use of this bacterium as an environmentally friendly and also cost-effective method, making it an attractive option for industries looking to reduce their environmental impact.

New alternative therapeutic strategies against Pseudomonas aeruginosa, an opportunistic multi-resistant pathogen with a myriad of virulence factors

Pseudomonas aeruginosa (PA) has emerged as a significant cause of Gram-negative infections, particularly in patients with impaired host defenses. It is one of the six ESKAPE pathogens that majorly cause severe nosocomial infections. In addition to biofilm formation, PA possesses various virulence factors. It can be life-threatening due to his remarkable capacity to resist antibiotics, either intrinsically, developing adaptative resistance, or following the acquisition of resistance genes. The situation worsens when these mechanisms co-exist, conferring worrying multi-resistant phenotypes. Therapeutic options are becoming limited, which has led to the development of new antibiotics and novel alternative therapeutic strategies that require the exploration of other therapeutic avenues. Although mostly at the preclinical stages, many recent studies have reported several innovative therapeutic technologies that have demonstrated pronounced effectiveness in fighting against drug-resistant Pa strains. This literature review aims to discuss the mechanism of pyocyanic bacillus resistance to antibiotics, highlight the current state of some novel antibiotics and combination therapies, and the new alternative therapeutic approaches for treating PA infections.

Detection of ESBLs and carbapenemases among Enterobacteriaceae isolated from diabetic foot infections in Ouargla, Algeria

INTRODUCTION

The emergence and rapid spread of Enterobacteriaceae carrying extended spectrum beta-lactamases (ESBLs) and carbapenemases represent a great threat to clinical treatment due to their multi-drug resistance. This study investigated ESBLs and carbapenemases encoding genes in Enterobacteriaceae collected from diabetic foot infections (DFIs) in Ouargla, southern Algeria.

METHODOLOGY

A total of 70 Enterobacteriaceae strains were recovered from 76 patients with DFI between February 2017 and April 2018. Antimicrobial susceptibility testing was performed using the disc diffusion method, and the presence of bla genes was detected using polymerase chain reaction (PCR) and DNA sequencing. The genetic transfer of the plasmids was carried out by conjugation using the broth mating method.

RESULTS

The most common isolate was Proteus mirabilis, followed by Escherichia coli, Morganella morganii and Klebsiella pneumoniae. The prevalence of ESBL and carbapenemase-producing Enterobacteriaceae was 11.42% and 2.85 % respectively. Plasmid-mediated AmpC was detected in 5.71% isolates. Conjugation experiments showed the transferability of blaCTX-M-2.

CONCLUSIONS

Our findings support the view that various pathogens found in DFIs differ from one part of the country to another. This study reports the first description of metallo-β-lactamase NDM-5 producing Klebsiella pneumoniae clinical isolate in Algeria.

Antimicrobial and antioxidant activities of Streptomyces species from soils of three different cold sites in the Fez-Meknes region Morocco

The increasing demand for new bioactive compounds to combat the evolution of multi-drug resistance (MDR) requires research on microorganisms in different environments in order to identify new potent molecules. In this study, initial screening regarding the antimicrobial activity of 44 Actinomycetes isolates isolated from three soil samples from three different extremely cold sites in Morocco was carried out. Primary and secondary screening were performed against Candida albicans ATCC 60,193, Escherichia coli ATCC 25,922, Staphylococcus aureus ATCC 25,923, Bacillus cereus ATCC 14,579, other clinical MDR bacteria, and thirteen phytopathogenic fungi. Based on the results obtained, 11 active isolates were selected for further study. The 11microbial isolates were identified based on morphological and biochemical characters and their molecular identification was performed using 16S rRNA sequence homology. The UV-visible analysis of dichloromethane extracts of the five Streptomyces sp. Strains that showed high antimicrobial and antioxidant (ABTS 35.8% and DPPH 25.6%) activities revealed the absence of polyene molecules. GC-MS analysis of the dichloromethane extract of E23-4 as the most active strain revealed the presence of 21 volatile compounds including Pyrrolopyrazine (98%) and Benzeneacetic acid (90%). In conclusion, we studied the isolation of new Streptomyces strains to produce new compounds with antimicrobial and antioxidant activities in a cold and microbiologically unexplored region of Morocco. Furthermore, this study has demonstrated a significant (P < 0.0001) positive correlation between total phenolic and flavonoid contents and antioxidant capacity, paving the way for the further characterization of these Streptomyces sp. isolates for their optimal use for anticancer, antioxidant, and antimicrobial purposes.

Environmental surveillance of Legionella pneumophila in hot water systems of hotels in Morocco

OBJECTIVE

Environmental monitoring of Legionella in hot water systems of hotels in Morocco was performed during the period from January 2016 to April 2018. A total of 149 water samples from 118 different hotels were analyzed.

METHODS

A total of 149 water samples from 118 different hotels were analyzed. Possible risk factors were prospectively recorded, and data were analyzed in connection with building and plumbing systems characteristics. Data about building and risk factors were collected through a questionnaire survey.

RESULTS

Out of the 149 samples, 77(51.7%) were positive for L. pneumophila. Serological typing of the isolates revealed that 54 (70.1%) are L. pneumophila serogroup 2-15 and 23 (29.9%) are L. pneumophila serogroup 1. 56.8% of all buildings were colonized by L. pneumophila. Counts were over 1,000 CFU/L in 44%. Contamination was strongly correlated with temperature in the circulation, the age of the premise plumbing and the size of the building.

CONCLUSIONS

The results showed a relevant exposure to L. pneumophila in the community and the identified risk factors can serve as indicators for risk assessment and relevant actions.

Whole genomic comparative analysis of Streptococcus pneumoniae serotype 1 isolates causing invasive and non-invasive infections among children under 5 years in Casablanca, Morocco

BACKGROUND

Streptococcus pneumoniae serotype 1 remains a leading cause of invasive pneumococcal diseases, even in countries with PCV-10/PCV-13 vaccine implementation. The main objective of this study, which is part of the Pneumococcal African Genome project (PAGe), was to determine the phylogenetic relationships of serotype 1 isolates recovered from children patients in Casablanca (Morocco), compared to these from other African countries; and to investigate the contribution of accessory genes and recombination events to the genetic diversity of this serotype.

RESULTS

The genome average size of the six-pneumococcus serotype 1 from Casablanca was 2,227,119 bp, and the average content of coding sequences was 2113, ranging from 2041 to 2161. Pangenome analysis of the 80 genomes used in this study revealed 1685 core genes and 1805 accessory genes. The phylogenetic tree based on core genes and the hierarchical bayesian clustering analysis revealed five sublineages with a phylogeographic structure by country. The Moroccan strains cluster in two different lineages, the five invasive strains clusters altogether in a divergent clade distantly related to the non-invasive strain, that cluster with all the serotype 1 genomes from Africa.

CONCLUSIONS

The whole genome sequencing provides increased resolution analysis of the highly virulent serotype 1 in Casablanca, Morocco. Our results are concordant with previous works, showing that the phylogeography of S. pneumoniae serotype 1 is structured by country, and despite the small size (six isolates) of the Moroccan sample, our analysis shows the genetic cohesion of the Moroccan invasive isolates.

Antimicrobial Susceptibility Patterns of Legionella spp. Strains Isolated from Water Systems in Morocco

Objective: Legionella is a waterborne pathogen that causes a severe form of pneumonia called Legionnaires' diseases, which is normally acquired by inhalation of aerosols containing Legionella originating from natural and man-made water systems. The aim of this study was to describe the level of antimicrobial susceptibility of environmental Legionella spp. strains to preferred and recommended therapeutic agents to treat Legionella disease. Methods: The minimum inhibitory concentrations (MICs) of 60 environmental Legionella spp. strains were tested using the broth dilution method. Susceptibility testing was performed for 12 antimicrobial agents: macrolides (erythromycin, azithromycin [AZI], and clarithromycin [CLA]), fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin, and gemifloxacin), a ketolide (telithromycin), cefotaxime (CEF), tigecycline (TIG), doxycycline (DOX), and rifampicin (RIF). Results: All tested strains of Legionella spp. were inhibited by low concentrations of fluoroquinolones and macrolides. Regarding the macrolides, CLA was the most active antibiotic, and AZI was the least active. RIF was the most effective antibiotic against the isolates in vitro. All isolates were inhibited by the following antibiotics (in decreasing order of their MICs): DOX>CEF>TIG. Conclusions: No resistance against these drugs was detected, and all isolates were inhibited by low concentrations of the tested antibiotics. Susceptibility testing of environmental Legionella spp. isolates must be monitored often to detect and evaluate the possible development of antibiotic resistance.

Dissemination of carbapenem-resistant Acinetobacter baumannii strains carrying the bla GES, bla NDM and bla OXA23 in Morocco

Background

Acinetobacter baumannii is a microorganism which has been classified by the World Health Organization in the list of the bacterial strains that pose the biggest danger to human health. This study was performed to determine the susceptibility profile to carbapenems and to detect carbapenemases production in 111 A. baumannii isolates. Among these 30 are environmental isolates and 81 are from the three major hospitals in Morocco.

Methods

All strains of A. baumannii were tested against diverse antimicrobial agents (13 antibiotic drugs) by the agar diffusion test. Minimum inhibitory concentration (MIC) of imipenem on carbapenem-resistant strains (CRAB) was determined by the E-test technique. Simple phenotypic tests were used to detect carbapenemases and metallo-β-lactamases (MBLs) production including the modified Hodge test, EDTA test, and the cloxacillin test. The presence of carbapenemases-encoding resistance genes of CRAB strains was examined using polymerase chain reaction (PCR).

Results

Carbapenem resistance was observed in 23 clinical Acinetobacter isolates showing dissemination of the multiresistance profile. Molecular biology techniques indicated that all these strains encoded the naturally occurring bla _OXA-51-like gene and were proved as A. baumannii. The bla _OXA-23 gene was detected in 16 strains (69.6%). The metallo-β-lactamase bla _NDM gene was detected in five isolates (21.7%). GES-type carbapenemases were found in 15 strains, the existence of three classes of carbapenemases (bla _GES, bla _NDM, and bla _OXA-23) was detected in three strains, while none of the CRAB isolates contained the bla _OXA-58, bla _OXA-24, bla _VIM, bla _OXA-48 or bla _KPC encoding genes.

Conclusions

This study established baseline proof of three classes of carbapenemases producing A. baumannii in Morocco, showing the important role of surveillance in controlling their spread.

Virulence and Antibiotic Resistance Patterns in E. coli, Morocco

Of 28 non-duplicate isolates of Escherichia coli recovered from yellow-legged Larus michahellis in Morocco, 92.86% were resistant to more than three antibiotics and 71.4% were multidrug resistant. Phylogenetic group A was most predominant (57.14%), followed by B1 (18%), B2 (14.28%) and F (10.71%). One isolate was resistant to ertapenem and contained the bla_OXA-48 gene. The plasmid-mediated quinolone resistance determinants were detected in nine isolates (aac(6')-Ib-cr, qnrS1, qnrB1). Thirteen isolates carried one of the Shiga toxin E. coli-associated genes: stx1 (n = 6), stx2 (n = 5) and eae (n = 2) genes. Our data support the idea that gull feces may create potential public health risk.

Occurrence of genes encoding aminoglycoside-modifying enzymes in Escherichia coli isolates from chicken meat

1. The aim of the experiment was to determine the occurrence of genes encoding aminoglycoside-modifying enzymes (AMEs) in Escherichia coli isolates recovered from chicken meat.2. Antibiotic sensitivity was tested using the disc diffusion test. AMEs and virulence profile were determined by PCR/sequencing.3. Out of 195 meat samples collected, 185 (95%) isolates were identified as E. coli. Disc diffusion showed a resistance value of 22% (n = 42) for at least one of the antibiotic aminoglycosides (AGs) tested (tobramycin, gentamycin, amikacin and kanamycin). PCR screening showed the presence of three classes of AMEs, namely, aac(3)-II (12%), aac(6')-Ib (7%) and aac(2')-Ia (5%). Eight of the 42 isolates were positive for the stx₁ and sxt₂ genes and were defined as Shiga toxin-producing E coli., while the eae gene was positive in one strain. Among the 42 isolates, group A was the predominant phylogenetic identified (76%), followed by group D (21%). One isolate belonged to subgroup B2₃.4. The results suggested that chicken meat could be an important reservoir of AMEs, and pose a potential risk by dissemination of resistance to humans through the food chain.

Characterization of uropathogenic ESBL-producing Escherichia coli isolated from hospitalized patients in western Algeria

Introduction: The aim of this study is to assess the prevalence and molecular characterization of uropathogenic Extended spectrum β-lactamases (ESBLs) producing Escherichia coli. Methodology: During 3 years, all hospitalized patients at the University-affiliated hospital of Tlemcen and presenting urinary tract infections caused by E. coli were considered as potential study participants. These E. coli isolates were examined phenotypically for ESBL production. ESBL strains were subjected to antimicrobial susceptibility testing and were investigated for the presence of plasmid mediated quinolone resistance genes, 16SrRNA methylase genes and virulence genes by using conventional PCR and DNA sequencing. The molecular characterization of ESBL strains was established by phylogenetic grouping method and ERIC-PCR. Results: The overall prevalence of ESBL was 32.5%. The blaCTX-M-15 was the most frequently detected in ESBL isolates, followed by blaCTX-M-14, blaCTX-M-28, blaCTX-M-1 and blaSHV-12 respectively. The plasmid-mediated quinolone resistance genes were detected in the 15 ESBL strains with the aac(6’)-Ib-cr gene was the most detected followed by qnrB1 and qnrA1 gene respectively. Among the 22 ESBL isolates resistant to gentamicin and amikacin, the 16SrRNA methylase genes were detected in 4 isolates. The sfa and pap virulent genes were founds in 26% and 22% of isolates receptively. The genotyping analysis of all strains revealed that almost were belonged to phylogenetic groups A1 and A0 and fourteen distinct clones. Conclusion: The emergence of uropathogenic ESBL isolates and the high rate of blaCTX-M are alarming in Algeria. Strict measure must be required to control the further spread of these strains in Algerian hospitals.

Antibacterial activity of cinnamon essential oils and their synergistic potential with antibiotics

The objective of this study was to evaluate the antibacterial activity of Cinnamomum cassia (cinnamon) essential oil (EO) alone and in combination with some classical antibiotics against three multidrug-resistant bacteria, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, to search a possible synergy. The antibacterial activity of all tested compounds was determined by agar disc diffusion and minimum inhibitory concentration assays. The checkerboard method was used to quantify the efficacy of cinnamon EO in combination with these antibiotics. Fractional inhibitory concentrations were calculated and interpreted as synergy, addition, indifferent, or antagonism. A synergistic interaction was shown against S. aureus with the combination cinnamon EO and ampicillin or chloramphenicol and against E. coli when cinnamon EO was combined with chloramphenicol. However, the combination of cinnamon oil and streptomycin displayed additive effects against all bacteria stains. The combinations of cinnamon EO and antibiotics can be used as an alternative therapeutic application, which can decrease the minimum effective dose of the drugs, thus reducing their possible adverse effects and the costs of treatment.

Analysis of amino acid motif of penicillin-binding proteins 1a, 2b, and 2x in invasive Streptococcus pneumoniae nonsusceptible to penicillin isolated from pediatric patients in Casablanca, Morocco

OBJECTIVES

This study aimed to investigate the nature of the amino acid motifs found in PBPs of Streptococcus pneumoniae isolates in invasive diseases from pediatric patients at Casablanca, Morocco. Five penicillin-susceptible (PSSP), ten penicillin-intermediate (PISP), and fifteen penicillin-resistant S. pneumoniae (PRSP) were studied by PCR-RFLP and DNA sequencing of the pbp1a, - 2b, and - 2x genes.

RESULTS

There were no changes in the conserved motifs of PBP1a, PBP2b and PBP2x for PSSP strains. Substitution close to PBP1a conserved motifs were found in all PRSP isolates and six/five PISP. Analysis of PBP2b showed that all but one of the 10 PISP strains and all PRSP had substitutions. Substitution close to PBP2x motifs showed that all but three of the 10 PISP strains and all PRSP had substitutions in tow conserved motifs. A total of 6, 11 and 10 genotypes were found after analysis of pbp1a, pbp2b, and pbp2x, respectively. The penicillin-nonsusceptible S. pneumoniae isolated in Casablanca share most amino acid substitutions of those reported worldwide, but they occurred among pneumococci with low level resistance to b-lactams.

Adhesion of Legionella pneumophila on glass and plumbing materials commonly used in domestic water systems

We aimed to investigate the adhesion of Legionella pneumophila serogroup1 and L. pneumophila serogroup2-15 on glass, galvanized steel, stainless steel, copper, Polyvinyl chloride(PVC), Cross-linked polyethylene(PEX-c) and Polypropylene Random Copolymer(PPR). The surface physicochemical properties of both bacterial cells and materials were estimated through contact angle measurements. The roughness and surface topography of the materials were evaluated by Atomic Force Microscopy. The two L. pneumophila serogroups and plumbing materials showed a hydrophobic character, while glass surface was hydrophilic. All strains were adhered to all materials with the exception of copper. The result showed that the adhesion of both L. pneumophila sg1 and sg2-15 was systematically expressed with high intensity on galvanized steel followed by PVC, PEX-c, PPR, stainless steel and the low intensity on glass. The extent of adhesion is in correlation with the surface roughness and acid-bases interactions, while hydrophobicity seems to have no effect in adhesion intensity.

Clonal Analysis of Clinical and Environmental Pseudomonas aeruginosa Isolates from Meknes Region, Morocco

From 123 clinical and environmental Pseudomonas aeruginosa isolates, 24 strains were selected for their similar antibioresistance, virulence and biofilm formation profiles, to examine their diversity and occurrence of clones within two hospitals and different natural sites in Meknes (Morocco). Pulsed-field gel electrophoresis, using DraI enzyme, didn't reveal a close relationship between clinical and environmental isolates nor between strains of the two hospitals. 19 genotypes were obtained, including two virulent environmental clones and three clinical clones virulent and resistant to antibiotics. Intra-hospital transmission of high-risk clones detected, in and between wards, constitutes a great public health concern.

Molecular characterization of penicillin non-susceptible Streptococcus pneumoniae isolated before and after pneumococcal conjugate vaccine implementation in Casablanca, Morocco

Background

Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide, especially among children and the elderly. The ability to effectively treat pneumococcal infection has been compromised due to the acquisition of antibiotic resistance, particularly to β-lactam drugs. This study aimed to describe the prevalence and molecular evolution of penicillin non-susceptible S. pneumoniae (PNSP) isolated from invasive diseases before and after pneumococcal conjugate vaccine implementation in Casablanca, Morocco.

Methods

Isolates were obtained from the Microbiology Laboratory of Ibn Rochd University Hospital Centre of Casablanca. Serogrouping was done by Pneumotest Kit and serotyping by the Quellung capsular swelling. Antibiotic susceptibility pattern was determined by disk diffusion and E-test methods. The PNSP were analyzed by pulsed-field gel electrophoresis (PFGE) and by genotyping of pbp1a, pbp2b, and pbp2x genes.

Results

A total of 361 S. pneumoniae isolates were collected from 2007 to 2014. Of these isolates, 58.7% were obtained before vaccination (2007–2010) and 41.3% after vaccination (2011–2014). Of the 361 isolates, 80 were PNSP (22.2%). Generally, the proportion of PNSP between pre- and post-vaccination periods were 31 and 13% (p = 0.009), respectively. The proportion of PNSP isolated from pediatric and adult (age > 14 years) patients decreased from 34.5 to 22.9% (p = 0.1) and from 17.7 to 10.2% (p = 0.1) before and after vaccine implementation, respectively. The leading serotypes of PNSP were 14 (33 vs. 57%) and 19A (18 vs. 14%) before and after vaccination among children. For adults, serotypes 19A (53%) and 23F (24%) were the dominant serotypes in the pre-vaccination period, while serotype 14 (22%) was the most prevalent after vaccination. There were 21 pbp genotypes in the pre-vaccination period vs. 12 for post-vaccination period. PFGE clustering showed six clusters of PNSP grouped into three clusters specific to pre-vaccination period (clusters I, II and III), two clusters specific to post-period (clusters V and VI) and a cluster (IV) that contained clones belonging to the two periods of vaccination.

Conclusion

Our observations demonstrate a high degree of genetic diversity among PNSP. Genetic clustering among PNSP strains showed that they spread mainly by a restricted number of PNSP clones with vaccine serotypes. PFGE clustering combined with pbp genotyping revealed that vaccination can change the population structure of PNSP.

Occurrence of plasmid-mediated quinolone resistance and virulence genes in avian Escherichia coli isolates from Algeria

INTRODUCTION

The emergence and spread of quinolone-resistant Escherichia coli in poultry products puts consumers at risk of exposure to the strains of E. coli that resist antibiotic treatment. The objective of this study was to define the prevalence and virulence potential of poultry-associated nalidixic acid (NAL)-resistant E. coli in the Annaba city, Algeria.

METHODOLOGY

In total, 33 samples of retail chicken meat were purchased from various butcher shops and examined for bacterial contamination with NAL-resistant E. coli. These isolates were subjected to antimicrobial susceptibility testing and were also investigated for the presence of plasmid-mediated quinolone resistance (PMQR) genes and virulence genes using conventional polymerase chain reaction (PCR) and DNA sequencing. Phylogenetic grouping of the NAL-resistant E. coli isolates was determined by the conventional multiplex PCR method.

RESULTS

Twenty-nine (87.8%) products yielded NAL-resistant E. coli. Antibiograms revealed that 96.55% of NAL-resistant E. coli isolates were multidrug resistant (MDR). Resistance was most frequently observed against sulfamethoxazole-trimethoprim (96.6%), tetracycline (96.6%), ciprofloxacin (72%), and amoxicillin (65.5%). Group A was the most prevalent phylogenetic group, followed by groups D, B1, and B2. The PMQR determinants were detected in three isolates with qnrB72 and qnrS1 type identified. Four (13.8%) isolates carried one of the Shiga toxin E. coli-associated genes stx1, stx2, and ehxA alleles.

CONCLUSIONS

The high prevalence of NAL-resistant E. coli isolated from retail chicken meat with detection of MDR E. coli harboring Shiga toxin genes in this study gives a warning signal for possible occurrence of foodborne infections with failure in antibiotic treatment.

Genotypic characterization of quinolone resistant-Escherichia coli isolates from retail food in Morocco

This study was conducted to assess the retail food as a possible vehicle for antimicrobial resistant, particularly quinolones resistant and pathogenic Escherichia coli. We determined the prevalence and characteristics of nalidixic acid (Nal) resistant E. coli isolates from diverse retail food samples. In all, 70 (28%) of 250 E. coli isolates studied were Nal-resistant E. coli and 91% of these were multi-drug resistant. Plasmid mediated quinolone resistance genes were identified in 32 isolates, including aac(6')-Ib-cr (n = 16), qnrS1 (n = 11) and qnrB19 (n = 7). Mutations in gyr A and par C genes were detected among 80% of the isolates, and the isolates showed substitution Ser83-Leu and Asp87-Asn in gyrA and Ser80-Ile in parC. In addition, three different gene cassettes were identified (aadA1, aadA7, aac(3)-Id) in 18%. Virulence-associated genes stx1, eae, sfa, hlyA and stx2 were found in six (8%), three (4%), two (3%), three (4%) and three (4%) isolates, respectively. E. coli isolates of phylogenetic group A were dominant (64%, 45/70). Pulsed field gel electrophoresis revealed none epidemiological relationship between these isolates. The results of this work report the higher frequency of Nal-resistant E. coli isolates from Moroccan retail food samples including MDR and pathogenic isolates.

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.