Clonal diversity and detection of carbapenem resistance encoding genes among multidrug-resistant Acinetobacter baumannii isolates recovered from patients and environment in two intensive care units in a Moroccan hospital

Abstract

BackgroundCarbapenem-resistant Acinetobacter baumannii has recently been defined by the World Health Organization as a critical pathogen. The aim of this study was to compare clonal diversity and carbapenemase-encoding genes of A. baumannii isolates collected from colonized or infected patients and hospital environment in two intensive care units (ICUs) in Morocco.MethodsThe patient and environmental sampling was carried out in the medical and surgical ICUs of Mohammed V Military teaching hospital from March to August 2015. All A. baumannii isolates recovered from clinical and environmental samples, were identified using routine microbiological techniques and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry. Antimicrobial susceptibility testing was performed using disc diffusion method. The carbapenemase-encoding genes were screened for by PCR. Clonal relatedness was analyzed by digestion of the DNA with low frequency restriction enzymes and pulsed field gel electrophoresis (PFGE) and the multi locus sequence typing (MLST) was performed on two selected isolates from two major pulsotypes.ResultsA total of 83 multidrug-resistant A. baumannii isolates were collected: 47 clinical isolates and 36 environmental isolates. All isolates were positive for the bla OXA51-like and bla OXA23-like genes. The coexistence of bla NDM-1 /bla OXA-23-like and bla OXA 24-like /bla OXA-23-like were detected in 27 (32.5%) and 2 (2.4%) of A. baumannii isolates, respectively. The environmental samples and the fecally-colonized patients were significantly identified (p < 0.05) as the most common sites of isolation of NDM-1-harboring isolates. PFGE grouped all isolates into 9 distinct clusters with two major groups (0007 and 0008) containing up to 59% of the isolates. The pulsotype 0008 corresponds to sequence type (ST) 195 while pulsotype 0007 corresponds to ST 1089.The genetic similarity between the clinical and environmental isolates was observed in 80/83 = 96.4% of all isolates, belonging to 7 pulsotypes.ConclusionThis study shows that the clonal spread of environmental A. baumannii isolates is related to that of clinical isolates recovered from colonized or infected patients, being both associated with a high prevalence of the bla OXA23-like and bla NDM-1genes. These findings emphasize the need for prioritizing the bio-cleaning of the hospital environment to control and prevent the dissemination of A. baumannii clonal lineages.Electronic supplementary materialThe online version of this article (10.1186/s13756-017-0262-4) contains supplementary material, which is available to authorized users.

Molecular typing of multi-drug resistant Acinetobacter baumannii isolates from clinical and environmental specimens in three Iranian hospitals by pulsed field gel electrophoresis

“…PFGE typing showed 8 different PFGE cluster (A, B, C, D, E, F, G, and H) with two major cluster A and G with 21 (30.4%) and 6 (23.2%) members, respectively, which contains up to 53.6% of all isolates. In our study, a close genetic relationship between clinical and environmental isolates of A. baumannii was observed that is consistent with other studies [4,21]. These results indicate that the hospital environment is frequently colonized by different A. baumannii clones, which may be responsible for the transmission of A. baumannii isolates between patients and their surroundings.…”

“…Of the 41 XDR A. baumannii strains isolated from patients' respiratory tracts, the bacteria isolated from tracheal aspirate specimens were the most common respiratory isolates, which is consistent with previous studies [19,20]. Consistent with the earlier study, the resistance rate of clinical and environmental isolates of A. baumannii to antibiotics was 95-100% and there was no significant difference between antibiotic resistance in clinical and environmental isolates (p > 0.05) [21]. One of the important features related to the virulence of A. baumannii is its ability to form biofilms.…”

The role of hospital environment in transmissions of multidrug-resistant gram-negative organisms

“…A recent study by Mody et al [40] demonstrated that contamination of patients' hands with MDRO is frequent and correlates with contamination of high-touch surfaces. Patients who were colonized or infected with CRAB were also shown to have higher environmental contamination with clonal CRAB compared to patients who were not [39,41]. The higher burden of MDRGN as usually observed in clinical infections, has been shown to increase environmental contamination [42,43].…”

“…Studies have demonstrated MDRGN contaminating dry surfaces in the hospital environment can also be responsible for the spread of infection [41]. HCWs responsible for cleaning and decontamination should be educated and monitored for strict adherence to protocols for decontamination of environment where patients infected/ colonized with MDRO are housed.…”

Evaluation of synergistic effect of tazobactam with meropenem and ciprofloxacin against multi-drug resistant Acinetobacter baumannii isolated from burn patients in Tehran

“…Moreover, Mohammadi et al reported similar results among hospitalized patients with burn infection in 2016 in Iran [32]. Therefore, it is not surprising that Chen et al in 2017 in China, Uwingabiye et al in 2017 in Morocco, and Nowak et al in 2017 in Greece, Italy, and Spain reported similar results in their investigations [33], [34], [35]. The percentage of bla OXA-24-like genes, which encode acquired carbapenemases, was 93.6% in the present study, followed by bla OXA-40-like with 48.9%.…”