Clonal, Plasmidic and Genetic Diversity of Multi-Drug-Resistant Enterobacterales from Hospitalized Patients in Tripoli, Libya.

Resistance to extended-spectrum cephalosporins (ESC) and carbapenems in Enterobacterales is a major issue in public health. Carbapenem resistance in particular is associated with increased morbidity and mortality. Moreover, such resistance is often co-harbored with resistance to non-beta-lactam antibiotics, and pathogens quickly become multi-drug-resistant (MDR). Only a few studies have been published on AMR in Libyan hospitals, but all reported worrisome results. Here, we studied 54 MDR isolates that were collected from 49 patients at the Tripoli University Hospital between 2019 and 2021. They were characterized using phenotypic methods, PCR and PFGE, and a sub-set of isolates were short- and long-read whole-genome sequenced. The results showed the frequent occurrence of Klebsiella pneumoniae (49/54), among which several high-risk clones were responsible for the spread of resistance, namely, ST11, ST17, ST101 and ST147. ESC and carbapenem resistance was due to a wide variety of enzymes (CTX-M, OXA-48, NDM, KPC), with their corresponding genes carried by different plasmids, including IncF-IncHI2 and IncF-IncR hybrids. This study highlights that implementation of infection prevention, control and surveillance measures are needed in Libya to fight against AMR.

Comparative study of multidrug-resistant bacterial infections in hospitals and community settings in the region of Monastir - Tunisia.

INTRODUCTION AND AIM: Multidrug resistance in bacteria has become a widespread scourge. The objective of this study is to investigate the epidemiology of multidrug-resistant bacteria (MDR) at Fattouma Bourguiba University Hospital of Monastir - Tunisia compared to the community and to define their antibiotic resistance profiles. METHODS: It was a retrospective and descriptive study over a period of 5 years (2016-2020) conducted at the microbiology department of Fattouma-Bourguiba University Hospital of Monastir - Tunisia. All MDR strains isolated from diagnostic microbiological samples collected from patients hospitalized in high-risk infectious departments and from outpatients were included in our study. RESULTS: A total of 4324 MDR among 16353 bacteria were isolated during the study period, i.e. a resistance rate of 26.4% with a predominance of hospital strains (80.3% versus 19.7% in the city). Third generation cephalosporin-resistant Enterobacteriaceae were the most prevalent and were mainly represented by extended-spectrum beta- lactamases (67.1% versus 83.4% in the community). Escherichia coli was the most frequent species (40.9%). It was frequently associated with resistance to fluoroquinolones (in more than 73% of cases). Imipenem-resistant Acinetobacter baumannii was mostly responsible for hospital acquired infections (77%). Co- resistances concerned most of the antibiotics but spared colistin. Methicillin-resistant Staphylococcus aureus infections were more frequent in the city (20.5% versus 19.3% in hospitals). Resistance associated was mainly to fusidic acid (49.6%). Glycopeptides have maintained their activity and only 2% were of decreased sensitivity to vancomycin. CONCLUSION: The emergence of MDR always represents a public health challenge. Thus, hygiene measures associated with an optimization of antibiotic therapy are necessary for a better control of their diffusion.

Comparative study of virulence factors among methicillin resistant Staphylococcus aureus clinical isolates.

BACKGROUND: Methicillin resistant Staphylococcus aureus (MRSA) is recognized worldwide as a leading cause of hospital and community infections. Biofilm formation by MRSA is an extremely important virulence factor to be understood. Our aim was to establish phenotypic and genotypic characterization of virulence factors among 43 MRSA clinical isolates in a Tunisian hospital. METHODS: We investigated enzymatic profiles, biofilm production and prevalences of genes encoding intracellular adhesion molecules (icaA and icaD), Microbial Surface Components Recognizing Adhesive Matrix Molecules genes (fnbA, fnbB and cna) and exoenzymes genes (geh, sspA and sspB). RESULTS: Our findings revealed that caseinase, gelatinase, lipase and lecithinase activities were detected in 100%, 100%, 76.6% and 93.3% of cases respectively. This study showed that 23 strains (76.7%) were slime producers on Congo red medium. Furthermore, 46.5% and 53.5% of isolates were respectively highly and moderately biofilm-forming on polystyrene. Significant association was found between both biofilm tests. PCR detection showed that 74.4%, 18.6%, 69.8%, 65.1% and 74.4% of isolates harbored fnbA, fnbB, icaA, icaD and cna genes respectively. In addition, 34.9%, 18.6% and 30.2% of MRSA strains were found positive for sspA, sspB and geh genes respectively. Further, statistical data showed that the presence of the fnbA and fnbB genes was significantly associated with a high biofilm production on polystyrene. However, no statistical association was observed for the icaA, icaD and cna genes. CONCLUSIONS: This study indicates that the detection of fnbA and fnbB contributing to the first step of biofilm formation has been predictable of high biofilm production. As studied factors contribute to MRSA virulence, this research could be of value in orienting towards the development of new preventive and therapeutic measures.