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In the present study, we provide a retrospective genomic surveillance of the SARS-CoV-2 pandemic in Lebanon; we newly sequence the viral genomes of 200 nasopharyngeal samples collected between July 2020 and February 2021 from patients in different regions of Lebanon and from travelers crossing the Lebanese–Syrian border, and we also analyze the Lebanese genomic dataset available at GISAID. Our results show that SARS-CoV-2 infections in Lebanon during this period were shaped by the turnovers of four dominant SARS-CoV-2 lineages, with B.1.398 being the first to thoroughly dominate. Lebanon acted as a dispersal center of B.1.398 to other countries, with intercontinental transmissions being more common than within-continent. Within the country, the district of Tripoli, which was the source of 43% of the total B.1.398 sequences in our study, was identified as being an important source of dispersal in the country. In conclusion, our findings exemplify the butterfly effect, by which a lineage that emerges in a small area can be spread around the world, and highlight the potential role of developing countries in the emergence of new variants. [ABSTRACT FROM AUTHOR]

Hepatitis E virus (HEV) is an important global public health concern. Several studies reported a higher HEV prevalence in patients undergoing regular hemodialysis (HD). In Lebanon, the epidemiology of HEV among HD patients has never been investigated previously. In this study, we examine the seroprevalence of HEV infection among 171 HD patients recruited from three hospital dialysis units in Tripoli, North Lebanon. Prevalence of anti-HEV IgG antibodies was evaluated in participant's sera using a commercial enzyme-linked immunosorbent assay (ELISA). The association of socio-demographic and clinical parameters with HEV infection in patients was also evaluated. Overall, 96 women and 75 men were enrolled in this study. Anti-HEV IgG antibodies were found positive in 37/171 HD patients showing a positivity rate of 21.63%. Among all examined variables, only the age of patients was significantly associated with seropositivity (P = 0.001). This first epidemiological study reveals a high seroprevalence of HEV infection among Lebanese HD patients. However, further evaluations that enroll larger samples and include control groups are required to identify exact causative factors of the important seropositivity rate in this population. [ABSTRACT FROM AUTHOR]

Background: A. baumannii has emerged as an important nosocomial pathogen with an outstanding ability to acquire multidrug resistant mechanisms. In this study, we investigate the molecular epidemiology and carbapenem resistance mechanisms of A. baumannii in Tripoli, Northern Lebanon. Methods: One hundred sixteen non-duplicate isolates isolated between 2011 and 2013 in different hospitals in Tripoli, Lebanon from Lebanese patients and wounded Syrian patients during Syrian war were studied. Antibiotic susceptibility testing was determined by agar disc diffusion and Etest. Carbapenemase-encoding genes were investigated by PCR. All isolates were typed by blaOXA-51-like sequence based typing (SBT) and 57 isolates were also analysed by MLST using Pasteur's scheme followed by eBURST analysis. Results: Of the 116 isolates, 70 (60 %) showed a carbapenem resistance phenotype. The blaOXA-23 with an upstream insertion of ISAba1 was the major carbapenem resistance mechanism and detected in 65 isolates. Five isolates, including four from wounded Syrian patients and one from a Lebanese patient, were positive for blaNDM-1. blaOXA-51-like SBT revealed the presence of 14 variants, where blaOXA-66 was the most common and present in 73 isolates, followed by blaOXA-69 in 20 isolates. MLST analysis identified 17 sequence types (ST) and showed a concordance with blaOXA-51-like SBT. Each clonal complex (CC) had a specific blaOXA-51-like sequence such as CC2, which harboured blaOXA-66 variant, and CC1 harbouring blaOXA-69 variant. NDM-1 producing isolates belonged to ST85 (4 Syrian isolates) and ST25 (1 Lebanese isolate). Conclusions: Our results showed a successful predominance of international clone 2 with a widespread occurrence of OXA-23 carbapenemase in Lebanese hospitals. These findings emphasise the urgent need of effective measures to control the spread of A. baumannii in this country. [ABSTRACT FROM AUTHOR]

Cryptosporidium spp. represent a major public health problem worldwide and infect the gastrointestinal tract of both immunocompetent and immunocompromised persons. The prevalence of these parasites varies by geographic region, and no data are currently available in Lebanon. To promote an understanding of the epidemiology of cryptosporidiosisin this country, the main aim of this study was to determine the prevalence Cryptosporidium in symptomatic hospitalized patients, and to analyze the genetic diversity of the corresponding isolates. Fecal specimens were collected in four hospitals in North Lebanon from 163 patients (77 males and 86 females, ranging in age from 1 to 88 years, with a mean age of 22 years) presenting gastrointestinal disorders during the period July to December 2013. The overall prevalence of Cryptosporidium spp. infection obtained by modified Ziehl-Neelsen staining and/or nested PCR was 11%, and children <5 years old showed a higher rate of Cryptosporidium spp. The PCR products of the 15 positive samples were successfully sequenced. Among them, 10 isolates (66.7%) were identified as C. hominis, while the remaining 5 (33.3%) were identified as C. parvum. After analysis of the gp60 locus, C. hominis IdA19, a rare subtype, was found to be predominant. Two C. parvum subtypes were found: IIaA15G1R1 and IIaA15G2R1. The molecular characterization of Cryptosporidium isolates is an important step in improving our understanding of the epidemiology and transmission of the infection. [ABSTRACT FROM AUTHOR]

This study analyzed 42 Acinetobacter baumannii strains collected between 2009–2012 from different hospitals in Beyrouth and North Lebanon to better understand the epidemiology and carbapenem resistance mechanisms in our collection and to compare the robustness of pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST), repetitive sequence-based PCR (rep-PCR) and blaOXA-51 sequence-based typing (SBT). Among 31 carbapenem resistant strains, we have detected three carbapenem resistance genes: 28 carried the blaOXA-23 gene, 1 the blaOXA-24 gene and 2 strains the blaOXA-58 gene. This is the first detection of blaOXA-23 and blaOXA-24 in Lebanon. PFGE identified 11 types and was the most discriminating technique followed by rep-PCR (9 types), blaOXA-51 SBT (8 types) and MLST (7 types). The PFGE type A'/ST2 was the dominant genotype in our collection present in Beyrouth and North Lebanon. The clustering agreement between all techniques was measured by adjust Wallace coefficient. An overall agreement has been demonstrated. High values of adjust Wallace coefficient were found with followed combinations: PFGE to predict MLST types  = 100%, PFGE to predict blaOXA-51 SBT = 100%, blaOXA-51 SBT to predict MLST = 100%, MLST to predict blaOXA-51 SBT = 84.7%, rep-PCR to predict MLST = 81.5%, PFGE to predict rep-PCR = 69% and rep-PCR to predict blaOXA-51 SBT = 67.2%. PFGE and MLST are gold standard methods for outbreaks investigation and population structure studies respectively. Otherwise, these two techniques are technically, time and cost demanding. We recommend the use of blaOXA-51 SBT as first typing method to screen isolates and assign them to their corresponding clonal lineages. Repetitive sequence-based PCR is a rapid tool to access outbreaks but careful interpretation of results must be always performed. [ABSTRACT FROM AUTHOR]

Objectives Bacteria multiresistant to antibiotics are widely supposed to be weakly virulent. However, the virulence traits of carbapenem-resistant Enterobacteriaceae have not been investigated. In this work, we investigated the virulence and resistance mechanism of an extraintestinal pathogenic Escherichia coli (ExPEC) strain (LEB15) that exhibited decreased susceptibility to carbapenems. Methods The MICs were determined by a microdilution method. The β-lactamase-encoding gene was identified by PCR and sequencing, and the genetic environment was analysed by PFGE and PCR mapping. The genetic background was investigated by multilocus sequence typing (MLST). Virulence-factor-encoding genes and pathogenic islands (PAIs) were detected by multiplex PCR. Virulence was assessed in a mouse sepsis model. Results Strain LEB15 produced a chromosomal OXA-48 carbapenemase. The complete blaOXA-48-encoding Tn1999.2 transposon was inserted in the LEB15 chromosome. The strain belonged to an MLST cluster of emerging ExPEC strains (ST-127/ST-22). It had a high pathogenic score and eight PAIs (I536, II536, III536, IV536, VI536, ICFT073, IICFT073 and IIJ96) and induced an unusually high lethality in the mouse sepsis model. Conclusions Strain LEB15 combines both an atypical broad accumulation of virulence factors, which confers a strong killer phenotype, and a decrease in susceptibility to carbapenems following the chromosomal acquisition of blaOXA-48. This association of virulence and carbapenemase in E. coli strains might pose major problems in the future for E. coli infection management. [ABSTRACT FROM PUBLISHER]

Summary: Objectives: The emergence of carbapenem-resistant Acinetobacter baumannii has been observed worldwide. We describe the first detection of A. baumannii carrying the bla NDM-1 gene in Lebanon, isolated from Syrian patients wounded during the civil war. Methods: Four carbapenem-resistant A. baumannii strains isolated in 2012 in the Tripoli Government Hospital, Lebanon, from civilians wounded during the Syrian war, were analysed. Susceptibility was determined by disk diffusion testing, and resistance to carbapenems was confirmed by Etest. The presence of bla OXA-23-like, bla OXA-24-like, bla OXA-58-like, bla OXA-143-like, and bla NDM was investigated by PCR. Clonal relationships were studied by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and bla OXA-51 sequence-based typing. Results: All isolates harboured the bla NDM-1 gene and were negative for other tested carbapenemases. They all belonged to the sequence type 85 and formed a single cluster by PFGE. Finally, bla OXA-51-like gene sequencing revealed the presence of the bla OXA-94 variant in all four isolates. Conclusion: These findings show that Syria constitutes a reservoir for NDM-1-producing bacteria. These results also highlight the need for effective measures to stop the threatening spread of such strains. [Copyright &y& Elsevier]

Quinolones are an important antimicrobial class used widely in the treatment of enterobacterial infections. Although there are multiple mechanisms of quinolone resistance, attention should be paid to plasmid-mediated genes due to their ability to facilitate the spread of quinolone resistance, the selection of mutants with a higher-level of quinolone resistance, and the promotion of treatment failure. Since their discovery in 1998, plasmid-mediated quinolone resistance (PMQR) mechanisms have been reported more frequently worldwide especially with the extensive use of quinolones in humans and animals. Nevertheless, data from the Arab countries are rare and often scattered. Understanding the prevalence and distribution of PMQR is essential to stop the irrational use of quinolone in these countries. This manuscript describes the quinolone resistance mechanisms and particularly PMQR among Enterobacteriaceae as well as their methods of detection. Then the available data on the epidemiology of PMQR in clinical and environmental isolates from the Arab countries are extensively reviewed along with the other associated resistance genes. These data shows a wide dissemination of PMQR genes among Enterobacteriaceae isolates from humans, animals, and environments in these countries with increasing rates over the years and a common association with other antibiotic resistance genes as bla CTX - M - 15. The incontrovertible emergence of PMQR in the Arab countries highlights the pressing need for effective stewardship efforts to prevent the selection of a higher rate of quinolone resistance and to preserve these crucial antibiotics. • Plasmid-mediated quinolone resistance (PMQR) mechanisms are emerged worldwide. • PMQR genes promote mutant selection with a higher level of resistance. • They are widely disseminated among Enterobacteriaceae isolates in Arab countries. • PMQR genes co-existed with other antibiotic resistance genes especially bla CTX - M - 15. [ABSTRACT FROM AUTHOR]

Cryptosporidium spp. are enteroparasites with worldwide distribution that infect the gastrointestinal tract of several vertebrates including humans. Human to human, zoonotic, foodborne and waterborne are reported as the main transmission routes of this parasite. Cryptosporidium spp. have been recognized as the predominant cause of waterborne and foodborne outbreaks. However, the epidemiological situation of cryptosporidiosis is not well known in Lebanon, a developing country with a population often affected by intestinal parasitic infections. This study was devoted to determine the prevalence and the genetic diversity of Cryptosporidium spp. in symptomatic hospitalized patients and in two children populations with different socio-economic level in North-Lebanon, as well as the risk factors associated with cryptosporidiosis. Fecal samples obtained from these populations were examined microscopically by modified Ziehl-Neelsen staining as well as nested PCR were done for the detection of Cryptosporidium oocysts. Out of 163 symptomatic hospitalized patients and 249 children, Cryptosporidium was present in 11% and 10.4% respectively according to microscopy examination and/or molecular tests. The genotyping showed the predominance of Cryptosporidium hominis in both populations. Subgenotype analysis of the isolates at the gp60 locus identified three subtypes IdA19, IbA10G2 and IaA18R3 for C. hominis and two subtypes IIaA15G1R1 and IIaA15G2R1 for C. parvum. Moreover, cryptosporidiosis was correlated with having meals outside home and presence of gastrointestinal symptoms especially diarrhea (p <0.05). This work constitutes the first molecular epidemiology study outlining risk factors associated with cryptosporidiosis in Lebanon. These findings support a need of a control program to prevent the circulation of this parasite. [ABSTRACT FROM AUTHOR]