Whole-Genome Sequencing of Six Strains of Salmonella enterica Isolated from Imported Meat in Algeria.

Nontyphoidal Salmonella (NTS) is one of the main causes of foodborne disease worldwide. In this report, we announce the first whole-genome sequencing of six strains of Salmonella enterica isolated from imported meat in Algeria. The genome sizes ranged from 4,601,209 to 4,958,962 bp. Antimicrobial resistance (AMR) genes, plasmids, and virulence factors were detected.

Whole-Genome Sequencing of Multidrug-Resistant Escherichia coli Strains Harboring the mcr-1 Gene, Isolated from Seawater of the Algiers Coast in Algeria.

Colistin resistance has emerged worldwide and is threatening the treatment efficacy of multiresistant Escherichia coli strains in humans and animals. Here, we communicate the whole-genome sequencing (WGS) of two colistin-resistant E. coli strains, M49 and M78, with genomes sizes of 4,947,168 and 5,178,716 bp, respectively, isolated from seawaters of the Algiers coast.

Mutations in ß-Lactamase AmpC Increase Resistance of Pseudomonas aeruginosa Isolates to Antipseudomonal Cephalosporins.

Mutation-dependent overproduction of intrinsic ß-lactamase AmpC is considered the main cause of resistance of clinical strains of Pseudomonas aeruginosa to antipseudomonal penicillins and cephalosporins. Analysis of 31 AmpC-overproducing clinical isolates exhibiting a greater resistance to ceftazidime than to piperacillin-tazobactam revealed the presence of 17 mutations in the ß-lactamase, combined with various polymorphic amino acid substitutions. When overexpressed in AmpC-deficient P. aeruginosa 4098, the genes coding for 20/23 of these AmpC variants were found to confer a higher (2-fold to >64-fold) resistance to ceftazidime and ceftolozane-tazobactam than did the gene from reference strain PAO1. The mutations had variable effects on the MICs of ticarcillin, piperacillin-tazobactam, aztreonam, and cefepime. Depending on their location in the AmpC structure and their impact on ß-lactam MICs, they could be assigned to 4 distinct groups. Most of the mutations affecting the omega loop, the R2 domain, and the C-terminal end of the protein were shared with extended-spectrum AmpCs (ESACs) from other Gram-negative species. Interestingly, two new mutations (F121L and P154L) were predicted to enlarge the substrate binding pocket by disrupting the stacking between residues F121 and P154. We also found that the reported ESACs emerged locally in a variety of clones, some of which are epidemic and did not require hypermutability. Taken together, our results show that P. aeruginosa is able to adapt to efficacious ß-lactams, including the newer cephalosporin ceftolozane, through a variety of mutations affecting its intrinsic ß-lactamase, AmpC. Data suggest that the rates of ESAC-producing mutants are ≥1.5% in the clinical setting.

New Delhi Metallo-beta-lactamase around the world: an eReview using Google Maps.

Gram-negative carbapenem-resistant bacteria, in particular those producing New Delhi Metallo-betalactamase-1 (NDM-1), are a major global health problem. To inform the scientific and medical community in real time about worldwide dissemination of isolates of NDM-1-producing bacteria, we used the PubMed database to review all available publications from the first description in 2009 up to 31 December 2012, and created a regularly updated worldwide dissemination map using a web-based mapping application. We retrieved 33 reviews, and 136 case reports describing 950 isolates of NDM-1-producing bacteria. Klebsiella pneumoniae (n= 359) and Escherichia coli (n=268) were the most commonly reported bacteria producing NDM-1 enzyme. Several case reports of infections due to imported NDM-1 producing bacteria have been reported in a number of countries, including the United Kingdom, Italy, and Oman. In most cases (132/153, 86.3%), patients had connections with the Indian subcontinent or Balkan countries. Those infected were originally from these areas, had either spent time and/or been hospitalised there, or were potentially linked to other patients who had been hospitalised in these regions. By using Google Maps, we were able to trace spread of NDM-1-producing bacteria. We strongly encourage epidemiologists to use these types of interactive tools for surveillance purposes and use the information to prevent the spread and outbreaks of such bacteria.

Molecular typing and characterization of TEM, SHV, CTX-M, and CMY-2 ß-lactamases in Enterobacter cloacae strains isolated in patients and their hospital environment in the west of Algeria.

OBJECTIVES: Enterobacter cloacae is a major nosocomial bacterium causing severe infections. A multicenter retrospective cohort study was conducted to collect baseline information on the molecular characteristics of ß-lactamase producing Enterobacter cloacae in the west of Algeria. MATERIALS AND METHODS: We report a series of 42 extended-spectrum ß-lactamase (ESBL) producing non-repetitive Enterobacter cloacae strains, collected in 3 university hospital (Tlemcen, Oran, and Sidi Bel Abbes). Antibiotic susceptibility testing (antibiogram and MIC) and screening for ESBL were performed according to the French Society for Microbiology guidelines. PFGE typing was used to characterize the clonality of all the strains. ß-lactamase genes (blaTEM, blaSHV, blaCTX-M, blaECB, and blaCMY-2) were amplified by PCR with specific primers. Plasmid isolation, electroporation, and conjugation experiments were carried out using standard methods. RESULTS: Sequence analysis revealed that most strains produced CTX-M type ESBLs (CTX-M-15 and CTX-M-3), whereas only 5 produced SHV-type ESBLs (SHV-12). The blaTEM gene was identified in all strains of Enterobacter cloacae. Several epidemic clones were determined. One strain was found to produce plasmid-mediated AmpC ß-lactamase (CMY-2); this gene was transferred from E. cloacae by electroporation. Conjugation experiments showed that blaCTX-M, blaTEM, and blaSHV were carried by conjugative plasmids of high molecular weight (≥70kb). CONCLUSION: The emergence of resistance genes is a public health problem.