Prevalence and molecular characterization of ESBL/pAmpC producing faecal Escherichia coli strains with widespread detection of CTX-M-15 isolated from healthy poultry flocks in Eastern Algeria.

The intensification of livestock farming has led to the widespread use of massive amounts of antibiotics worldwide. Poultry production, including white meat, eggs and the use of their manure as fertiliser, has been identified as one of the most crucial reservoirs for the emergence and spread of resistant bacteria, including E. coli in poultry as an important opportunistic pathogen representing the greatest biological hazard to human and wildlife health. Thus, this study aimed to analyse E. coli in the faecal carriage of healthy poultry flocks and to investigate the phenotypic and genotypic characteristics of antimicrobial resistance, including integrons genes and phylogenetic groups. A total of 431 cloacal swabs from apparently healthy poultry from four regions in Eastern Algeria from December 2021 to October 2022. 360 E. coli were isolated; from broilers (n = 151), broiler breeders (n = 91), laying hens (n = 72), and breeding hens (n = 46). Among this, 281 isolates exhibited multidrug resistance (MDR) phenotype, 17 of the 360 E. coli isolates exhibited ESBL, and one isolate exhibited both ESBL/pAmpC. A representative collection of 183 among 281 MDR E. coli was selected for further analysis by PCR to detect genes encoding resistance to different antibiotics, and sequencing was performed on all positive PCR products of blaCTX-M and blaCMY-2 genes. Phylogenetic groups were determined in 80 E. coli isolates (20 from each of the four kinds of poultry). The blaCTX-M gene was found in 16 (94.11 %) ESBL-producing E. coli isolates within 11 strains co-expressing the blaSHV gene and 8 strains co-expressing the blaTEM gene. Sequence analysis showed frequent diversity in CTX-M-group-1, with blaCTX-M-15 being the most predominant (n = 11), followed by blaCTX-M-1 (n = 5). The blaCMY-2 gene was detected only in one ESBL/pAmpC isolate. Among the 183 tested isolates, various antimicrobial resistance genes were found (number of strains) blaTEM (n = 121), blaSHV (n = 12), tetA (n = 100), tetB (n = 29), sul1(n = 67), sul2 (n = 32), qnrS (n = 45), qnrB (n = 10), qnrA (n = 1), catA1(n = 13), aac-(6')-Ib (n = 3). Furthermore, class 1 and class 2 integrons were found in 113 and 2 E. coli, respectively. The isolates were classified into multiple phylogroups, including A (35 %), B1 (27.5 %), B2 and D each (18.75 %). The detection of integrons and different classes of resistance genes in the faecal carriage of healthy poultry production indicates that commensal E. coli could potentially act as a reservoir for antimicrobial resistance, posing a significant One Health challenge encompassing the interconnected domains of human, animal health and the environment. Here, we present the first investigation to describe the diversity of blaCTX-M producing E. coli isolates with widespread detection of CTX-M-15 and CTX-M-1 in healthy breeders (Broiler and breeding hens) in Eastern Algeria.

Antibacterial effect of N-acetylcysteine and taurolidine on planktonic and biofilm forms of Enterococcus faecalis.

AIM: This study investigated the antimicrobial activity of taurolidine and N-acetylcysteine (NAC) on planktonic and biofilm Enterococcus faecalis phenotypes. MATERIALS AND METHODS: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of NAC and taurolidine were determined using broth microdilution, utilizing calcium hydroxide (CH), sodium hypochlorite, and chlorhexidine for comparisons. Thereafter, the ability of dentin powder to neutralize the antibacterial activity of NAC and taurolidine was studied. The efficacy of both antimicrobial agents on E. faecalis biofilms was examined quantitatively by exposure of 21-day-old E. faecalis biofilms on dentin disks. The cytotoxicity of human dental pulp fibroblast cells in contact with the extracts was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay. RESULTS: The MIC and MBC of NAC, taurolidine, and CH were not affected by pre-incubation in dentin powder. As verified by qualitative assay of E. faecalis biofilms, CH was the strongest bactericidal agent at all test dilutions, regardless of the presence of dentin powder. The antibacterial effect of NAC and taurolidine was significantly lower than that of CH at all test dilutions. At 48 h, all test agents showed similar, but high levels of cytotoxicity. CONCLUSION: NAC and taurolidine were effective against E. faecalis in planktonic state, at the expense of demonstrating cytotoxic effects. For both planktonic and biofilm forms of E. faecalis, neither NAC nor taurolidine offered any advantage over CH.

[Determination of hepatitis C virus genotypes among hepatitis C patients in Eastern Black Sea Region, Turkey]. / Dogu Karadeniz Bölgesi Hepatit C Hastalarinda Hepatit C Virusu Genotiplerinin Belirlenmesi.

Hepatitis C virus (HCV), the major cause of transfusion-associated hepatitis, is an important public health problem in the world as well as in Turkey. HCV is grouped as six distinct genotypes and a large number of closely-related subtypes. Genotyping of HCV is an important tool for providing epidemiological data, prediction of prognosis, and optimization of antiviral therapy. This study was carried out to determine the distribution of HCV genotypes in hepatitis C patients residing in different provinces of the Eastern Black Sea Region, Turkey. A total of 304 HCV-RNA positive cases (151 male, 153 female; age range: 11-93 years, mean age: 55.2 ± 13.3 years) who were admitted to the Molecular Microbiology Unit of Department of Medical Microbiology, Karadeniz Technical University Faculty of Medicine, between January 2009 to December 2012, were included in the study. HCV genotypes were detected in plasma samples of the patients by using commercial assays [INNO-LiPA HCV II (Innogenetics, Belgium) or Abbott RealTime HCV Genotype II (Abbott Molecular Inc, USA)]. Due to the ambiguous genotyping results in some samples with these methods, an in-house multiplex polymerase chain reaction (PCR) assay with genotype-specific primers was also used in the study. Similar to the previous reports from Turkey, our results showed that four HCV genotypes (1, 2, 3, and 4) prevailed in the Eastern Black Sea Region and the predominant genotype and subtype were genotype 1 (92.8%) and 1b (87.5%), respectively. Distribution of genotypes were observed to vary according to the province. Prevalences of subtype 1a, genotype 2, 3, and 4 were noted as 5.3%, 1.6%, 4.9%, and 0.7%, respectively. Furthermore, the samples from Giresun, Gumushane and Bayburt provinces, which are relatively less immigrated, had higher genotype 1, and the prevalence rates in the region was affected by the presence of non-citizen residents. This study is the first report on distribution of HCV genotypes in chronic hepatitis C patients living in the provinces of Eastern Black Sea Region. Moreover, genotype-specific multiplex PCR assay could be useful in resolving certain methodological problems such as "ghost bands" encountered in line probe assay (LiPA) and multiple genotypes (including genotype 4) observed in real-time PCR during the characterization of HCV genotypes seen in Turkey.