Dissemination of OXA-48- and NDM-1-Producing Enterobacterales Isolates in an Algerian Hospital.

Multidrug-resistant (MDR) Enterobacterales remain an increasing problem in Algeria, notably due to the emergence of carbapenemase producers. We investigated the molecular characteristics of carbapenem-resistant Enterobacterales isolates recovered from outpatients and inpatients in Eastern Algeria. Non-repetitive Enterobacterales with reduced susceptibility to carbapenems were consecutively collected from clinical specimens in Annaba University Hospital (Algeria) between April 2016 and December 2018. Isolates were characterized with regard to antibiotic resistance, resistome and virulome content, clonality, and plasmid support. Of the 168 isolates analyzed, 29 (17.3%) were carbapenemase producers and identified as K. pneumoniae (n = 23), E. coli (n = 5), and E. cloacae (n = 1). blaOXA-48 was the most prevalent carbapenemase-encoding gene (n = 26/29), followed by blaNDM-1 gene (n = 3/29). K. pneumoniae isolates harbored some virulence traits (entB, ugeF, ureA, mrkD, fimH), whereas E. coli had a commensal origin (E, A, and B1). Clonality analysis revealed clonal expansions of ST101 K. pneumoniae and ST758 E. coli. Plasmid analysis showed a large diversity of incompatibility groups, with a predominance of IncM (n = 26, 89.7%). A global dissemination of OXA-48-producing Enterobacterales in the Algerian hospital but also the detection of NDM-1-producing E. coli in community settings were observed. The importance of this diffusion must be absolutely investigated and controlled.

Colistin- and Carbapenem-Resistant Klebsiella pneumoniae Clinical_Isolates: Algeria.

This study investigates the molecular mechanisms of colistin and carbapenem resistance in Klebsiella pneumoniae ST101 strains. The three K. pneumoniae carried blaCTX-M-15, blaTEM-183, and blaSHV-106 genes and two coharbored blaOXA-48. As for colistin resistance, the isolates had amino acid substitutions in PmrA/B and a truncated mgrB gene in one isolate.

First Case of NDM-1-Producing Klebsiella pneumoniae in Annaba University Hospital, Algeria.

AIM: The aim of this study was to characterize two carbapenem-resistant Klebsiella pneumoniae isolates recovered from urine samples in a patient hospitalized at Annaba University hospital (Algeria) in 2014. RESULTS: Two K. pneumoniae isolates were studied because they proved resistant to almost all antibiotics tested with a high level resistance to ertapenem (minimum inhibitory concentration = 32 mg/L). The results of modified Hodge test and combined disk test (ROSCO Diagnostica, Taastrup, Denmark) were positive. The two isolates harbored the blaNDM-1 gene and one was also positive for blaCTX-M-15. Screening of aminoglycoside-modifying enzymes and plasmid-mediated quinolone resistance contents detected aac(6')-Ib-cr, aac(3')-II, qnrB2, and oqxAB in both isolates. Multilocus sequence typing demonstrated that the two isolates belonged to sequence type 147. However, repetitive sequence-based PCR and pulsed-field gel electrophoresis showed that they were not clonally related. The blaNDM-1 gene and all other resistant genes were contained on an IncR plasmid of c.a. 85 kb. CONCLUSIONS: This study comprises the first identification of NDM-1-producing K. pneumoniae in Algeria. We thus confirm the concerning worldwide dissemination of this carbapenemase that involves the emergence of the IncR plasmid and the success of the ST147 clonal complex harboring it.

Co-occurrence of blaNDM-1 with blaOXA-23 or blaOXA-58 in clinical multidrug-resistant Acinetobacter baumannii isolates in Algeria.

The aim of this study was to characterise the mechanisms of carbapenem resistance in Acinetobacter baumannii strains isolated in an Algerian hospital. A total of 43 imipenem-resistant A. baumannii clinical isolates collected between 2010 and 2013 were identified using API 20NE and were confirmed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). Antibiotic susceptibility testing was performed by the disk diffusion and Etest methods. Carbapenemase activity was detected using microbiological tests and PCR. Genetic transfer of the blaNDM-1 gene was performed by conjugation using sodium azide-resistant Escherichia coli J53 as recipient strain. Clonal relationships were studied by multilocus sequence typing (MLST) using partial sequences of the csuE and blaOXA-51 genes. All 43 A. baumannii isolates were resistant to imipenem with high minimum inhibitory concentrations (MICs) (>32µg/mL). The strains harboured blaOXA-23, blaNDM-1, blaOXA-58 and/or blaOXA-24 genes. Co-existence of blaNDM-1 and blaOXA-23 or blaOXA-58 was detected in two isolates and one isolate, respectively. NDM-1 plasmid transfer to E. coli J53 was successful only for one of the three strains harbouring both blaNDM-1 and blaOXA-23 or blaOXA-58. The phylogenetic tree obtained from concatenation of the partial sequences of csuE and blaOXA-51 showed that there was no genetic relationship between the isolates and the blaNDM-1 resistance gene. Here we report for the first time the co-occurrence of blaNDM-1 along with blaOXA-23 or blaOXA-58 in recent clinical isolates of A. baumannii from Northeast Algeria. These findings re-emphasise the dissemination and rapid spread of blaNDM-1 carbapenemase genes in multidrug-resistant clinical A. baumannii isolates in Algeria.

NDM-5 carbapenemase-encoding gene in multidrug-resistant clinical isolates of Escherichia coli from Algeria.

Here, we report the first autochthonous cases of infections caused by blaNDM-5 New Delhi metallo-ß-lactamase-producing Escherichia coli strains recovered from urine and blood specimens of three patients from Algeria between January 2012 and February 2013. The three isolates belong to sequence type 2659 and they coexpress blaCTX-M-15 with the blaTEM-1 and blaaadA2 genes.

Epidemiology of carbapenemase-producing Enterobacteriaceae and Acinetobacter baumannii in Mediterranean countries.

The emergence and global spread of carbapenemase-producing Enterobacteriaceae and Acinetobacter baumannii are of great concern to health services worldwide. These ß-lactamases hydrolyse almost all ß-lactams, are plasmid-encoded, and are easily transferable among bacterial species. They are mostly of the KPC, VIM, IMP, NDM, and OXA-48 types. Their current extensive spread worldwide in Enterobacteriaceae is an important source of concern. Infections caused by these bacteria have limited treatment options and have been associated with high mortality rates. Carbapenemase producers are mainly identified among Klebsiella pneumoniae, Escherichia coli, and A. baumannii and still mostly in hospital settings and rarely in the community. The Mediterranean region is of interest due to a great diversity and population mixing. The prevalence of carbapenemases is particularly high, with this area constituting one of the most important reservoirs. The types of carbapenemase vary among countries, partially depending on the population exchange relationship between the regions and the possible reservoirs of each carbapenemase. This review described the epidemiology of carbapenemases produced by enterobacteria and A. baumannii in this part of the world highlighting the worrisome situation and the need to screen and detect these enzymes to prevent and control their dissemination.

Outbreak of an armA methyltransferase-producing ST39 Klebsiella pneumoniae clone in a pediatric Algerian Hospital.

Here we report an outbreak of Klebsiella pneumoniae infections harboring extended spectrum ß-lactamases (ESBL) and armA 16Sr RNA methylase that were detected in pediatric and neonatal intensive care units during the 2010 and 2011 surveys of 100 clinical strains of K. pneumoniae from Annaba hospitals in Algeria. Antibiotic susceptibility testing was performed using the disk diffusion method. Minimum inhibitory concentrations of three classes of antibiotics were determined using the E. test. Standard polymerase chain reaction amplification and sequencing were performed using primers targeting ESBL, 16S ribosomal RNA (rRNA) methyltransferases, aminoglycoside-modifying enzymes (AMEs), and quinolone encoding genes. Clonal relationships among the clinical isolates were performed using multilocus sequence typing. From our clinical isolates, we found high rates of antimicrobial resistance that were linked to the presence of different ESBL encoding genes and AMEs, including 23 strains that harbored several ESBL encoding genes along with the 16S rRNA methyltransferase armA. Among these isolates, we identified a cluster of eight isolates of the ST39 clone between February and June 2010 in a pediatric ward, suggesting that an outbreak had occurred during this period. In conclusion, the emergence of multidrug-resistant clones, which were likely responsible for a nosocomial outbreak, is worrying because there are already limited options in those critical situations. Finally, we believe that surveillance should be implemented to monitor the risk of emergence and spread of carbapenemases in Algeria.

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

INTRODUCTION: Expended spectrum ß-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) ß-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 ß-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.

Molecular epidemiology of Enterococcus sp. isolated in a university hospital in Algeria.

BACKGROUND: The aim of this study was to describe the epidemiology of enterococci isolated from infections at an Algerian university hospital, and to evaluate the prevalence of vancomycin-resistant enterococci (VRE) and the clonal cluster present in this country. METHODS: Patients who presented at Annaba University Hospital with Enterococcus infections were prospectively included over a 1-y period (2010). All Enterococcus sp. isolated were characterized by antibiotic resistance, van and erm genes, repetitive sequence-based polymerase chain reaction (rep-PCR), multi-locus sequence typing (MLST), and virulence genes. RESULTS: A total of 125 Enterococcus isolates recovered from 125 patients (59% female; median age 54 y, range 2-86 y) were studied. No differences in epidemiological data were observed between infections by Enterococcus faecalis vs Enterococcus faecium. However a high proportion of E. faecium were resistant to ampicillin (95%). The prevalence of VRE, corresponding to 4 vanC1-Enterococcus gallinarum, was 3.2%. A high level of genomic diversity among strains was noted, with the importance of sequence type (ST) 78 (which belongs to clonal complex (CC) 17) in E. faecium and ST317 and CC2 in E. faecalis. CONCLUSIONS: This first study on enterococci isolated in Algeria shows the low prevalence of VRE, but the presence of clonal complexes linked to VRE and vancomycin-sensitive enterococci associated with hospital infections. Moreover the high level of macrolide resistance and/or ampicillin resistance in E. faecium suggests close monitoring of the epidemiology of these strains.