BACKGROUND: Corynebacterium pseudotuberculosis is the etiological agent of caseous lymphadenitis (CLA), a chronic and very common disease in sheep and goats, which can lead to severe economic losses in the livestock industry.OBJECTIVES: This study aims to investigate the prevalence of CLA in sheep in Kurdistan province of Iran using phenotypic and molecular methods, and assess the antibiotic resistance of isolated Corynebacterium pseudotuberculosis.METHODS: In this study, from September to March 2022, 270 samples of skin abscesses were collected from sheep in livestock farms of Kurdistan province. Immediately, using the cold chain system, the samples were transferred to the microbiology laboratory of the Faculty of Medicine at Kurdistan University of Medical Sciences. Identification of isolates was done using biochemical tests and polymerase chain reaction (PCR) method. The antibiotic resistance of the isolates was examined using the Kirby-Bauer disk diffusion method.RESULTS: Based on biochemical tests, out of 270 samples, 82 suspected to have Corynebacterium pseudotuberculosis. Out 82 samples, the presence of bacteria was confirmed in 76 samples by the PCR. The antibiotic sensitivity test showed that the isolates had high sensitivity to doxycycline and ceftriaxone and high resistance to streptomycin and kanamycin.CONCLUSIONS: The CLA has a high prevalence in sheep in Kurdistan province. According to high resistance rate of Corynebacterium pseudotuberculosis to streptomycin and kanamycin, it recommended to avoid treatment of CLA cases with these antibiotics.

BACKGROUND: Pigeons can be carriers for some human and animal pathogens, one of the most important of which is Escherichia coli. OBJECTIVES: This bacterium is responsible for outbreaks of many human diseases. Our objective was to determine the prevalence of Escherichia coli in cloacal area of pigeons in Tehran city (Iran), and determine  the prevalence of some virulence genes and also antibiotics resistance pattern of isolates. METHODS: Altogether 117 samples of pigeon feces were collected from cloacal swab. The identification of bacteria was done by culture on differential culture media. Then antibiotic susceptibility test was performed by disk diffusion method. Isolates were tested for the presence of virulence genes stx1, stx2, eae and hlyA using multiplex polymerase chain reaction. RESULTS: Escherichia coli were detected in 82.9% of 277 samples from pigeons. Sulfamethoxazole was the least effective drug (85.6% resistance), followed by tetracycline (83.5%). No resistance was detected to co-amoxiclav. The prevalence of stx1, stx2 and eaeA is 3.09%, 6.18% and 2.06% respectively and hlyA was not found in any of isolates. CONCLUSIONS: The frequency of stx1 and stx2 distribution in animals and birds is not well understood as yet. Due to the close relationship of humans with birds like pigeons and presence of STEC strains in apparently healthy birds, necessitates  considering  precise regulations to restrict and prevent the prevalence of this life- threatening virus in Iran.

Antimicrobial resistance (AMR) is a global public health threat for both human and veterinary medicine. Increasing evidence suggests that animals are important sources of AMR to humans; however, most of these studies focus on production animals. In order to determine the pattern of AMR in pets, mainly in dogs in Africa, a meta-analysis was performed with AMR studies conducted in African countries and published between January 2000 and January 2021 in four databases: Medline (PubMed), Scopus, Cab abstract and Google Scholar. Seven bacterial strains, namely Staphylococcus aureus, Escherichia coli, Salmonella spp., Pseudomonas aeruginosa, Streptococcus pyogenes, coagulase-negative Staphylococcus (SNC) and Staphylococcus pseudintermedius were included in this study. A total of 18 out of 234 indexed articles met the study criteria. The results revealed that multiple bacteria were resistant to various commonly used antibiotics including enrofloxacin, ciprofloxacin, gentamicin, amoxicillin, clavulanic acid, cotrimoxazole, streptomycin, tetracycline and chloramphenicol. Concerning multidrug resistance, E. coli strains came first with the highest prevalence of 98%, followed by P. aeroginosa (92%) and Salmonella spp. (53%). In contrast, the overall prevalence of multidrug resistance was low for S. aureus (18%) and S. pseudintermedius (25%). It is therefore urgent to find, as soon as possible, alternatives to replace these antibiotics, which have become ineffective in controlling these bacteria in dogs in Africa. Moreover, further metagenomic studies are needed to describe the full resistome and mobilome in dogs regardless of the bacteria.

International audience | South Africa is a large country of approximately 1.22 million km(2), made up of nine provinces with three climatic zones. Farming in the country is mostly defined by regional differences. Of the different organisms isolated from milk samples of dairy cows, Staphylococcus aureus poses a challenge to maintain udder health and wholesome dairy products for human consumption. Antibiotic resistant bacteria are therefore a potential health hazard. The objective of this study was to investigate the seasonal and regional relationships of antibiotic resistance of S. aureus, of which little is known. This study was undertaken to evaluate a data set of 3410 S. aureus isolates, taken from milk samples with a somatic cell count of > 400 000 cells/mL from commercial dairy herds. These isolates were tested for antimicrobial susceptibility using the Kirby Bauer method for ampicillin, cloxacillin, penicillin G, clindamycin, oxy-tetracycline, cephalexin, cefuroxime and tylosin. The samples were from 830 dairy herds, out of the estimated 2000 commercial dairy herds in South Africa. All the antibiotics tested, except for cephalosporins, showed a predicted prevalence of resistance of above 50% in most provinces, which is a concern. The lowest prevalence of resistance to the majority of the categories of antibiotics tested was present in KwaZulu-Natal during spring. The cephalosporins had the lowest levels of prevalence of bacterial resistance in Gauteng during winter. Resistance patterns of S. aureus to the eight antibiotics varied in the different seasons and provinces, possibly because of different weather conditions, and the action and spectrum of antibiotics.

Nontuberculous mycobacteria (NTM) are increasingly recognised as causative agents of opportunistic infections in humans for which effective treatment is challenging. There is very little information on the prevalence of NTM drug resistance in Poland. This study was aimed to evaluate the susceptibility to antibiotics of NTM, originally isolated from diseased ornamental fish. A total of 99 isolates were studied, 50 of them rapidly growing mycobacteria (RGM) (among which three-quarters were Mycobacterium chelonae, M. peregrinum, and M. fortuitum and the rest M. neoaurum, M. septicum, M. abscessus, M. mucogenicum, M. salmoniphilum, M saopaulense, and M. senegalense). The other 49 were slowly growing mycobacteria (SGM) isolates (among which only one was M. szulgai and the bulk M. marinum and M. gordonae). Minimum inhibitory concentrations for amikacin (AMK), kanamycin (KAN), tobramycin (TOB), doxycycline (DOX), ciprofloxacin (CIP), clarithromycin (CLR), sulfamethoxazole (SMX), isoniazid (INH) and rifampicin (RMP) were determined. The majority of the isolates were susceptible to KAN (95.95%: RGM 46.46% and SGM 49.49%), AMK (94.94%: RGM 45.45% and SGM 49.49%), CLR (83.83%: RGM 36.36% and SGM 47.47%), SMX (79.79%: RGM 30.30% and SMG 49.49%), CIP (65.65%: RGM 24.24% and SGM 41.41%), and DOX (55.55%: RGM 9.06% and SGM 46.46%). The majority were resistant to INH (98.98%: RGM 50.50% and SGM 48.48%) and RMP (96.96%: RGM 50.50% and SGM 46.46%). The drug sensitivity of NTM varies from species to species. KAN, AMK, CLR and SMX were the most active against RGM isolates, and these same four plus DOX and CIP were the best drugs against SGM isolates.

Integrons are mobile DNA elements that allow for acquisition and dissemination of antibiotic-resistance genes among pig farm-derived bacteria. Limited information is available on integrons of Staphylococcus aureus from pig farms. The aim of this study was to characterise and investigate the prevalence of class 1 and 2 integrons in multi-drug resistant (MDR) S. aureus isolates from pig farms. A total of 724 swabs were collected from 12 pig farms in Chongqing, China, and examined by conventional microbial and molecular methods. In total, 68 isolates were S. aureus, 57 of which were methicillin resistant (MRSA). All 68 isolates were MDR strains and carried integrons, of which 88.2% (60/68) harboured both class 1 and 2. In addition, 85.3% (58/68) of the class 2 integron-positive isolates carried the β-lactam resistance gene (blaTEM₋₁), and 66.7% (40/60) of the class 1 integron–positive isolates carried the aadA1c, aadA1 or dfrA1 gene for respective streptomycin and spectinomycin or trimethoprim resistance. Class 1 and 2 integrons are common among the pig farm-derived S. aureus isolates. On account of their significance for public health, the prevalence of the integrons and their associated resistance genes in pig farm-derived S. aureus isolates should be paid special attention.

Due to increasing bacterial antibiotic resistance and the consumers’ tendency to choose organic products, cattle farmers are interested in alternative methods of calf diarrhoea treatment. This is a major challenge for veterinarians. Few methods of non-antibiotic treatment that bring satisfactory results have been reported in the related literature so far. In this article, the authors compare different non-antibiotic methods of diarrhoea prevention and treatment in calves. Among the alternatives discussed are herbs, probiotics, prebiotics and synbiotics, lactoferrin, and bacteriophages. It was found that the best results could be achieved through the use of pro-, pre- and synbiotics. However, the authors would like to point out that with the expansion of knowledge about the practical use of broad-scale bacteriophages, they could be the best alternative to antibiotics.

The article describes the occurrence and phylogenetic relationship of Salmonella isolates found in subcutaneous abscesses of leopard geckos. The aim of the study was to determine the cause of the abscesses and to characterise isolated Salmonella strains. Samples of abscesses from five animals and internal organs (lungs, liver, and gut) of three of them were tested for Salmonella according to the PN-EN ISO 6579:2002/A1:2007 standard. The antimicrobial resistance was evaluated by minimal inhibitory concentrations and the genetic similarity of the isolates was assessed with pulsed field gel electrophoresis (PFGE). In total, seventeen Salmonella isolates belonging to five different serovars were found to be susceptible to all tested antimicrobials except streptomycin. The serovars were S. Hadar, S. Fluntern, S. Tennessee, S. enterica subsp. salamae 55:k:z₃₉, and S. Kentucky. Up to three serovars from different organs were isolated from the same individual. In two geckos, Salmonella were detected in the lungs. In three serovars, XbaI-PFGE typing revealed indistinguishable isolates from organs and abscesses. Multiple Salmonella serovars might be involved in abscess formation and infections. The occurrence of the same PFGE profiles of the isolates may testify to the role of opportunistic organisms in causing infection.

Land application of manure that contains antibiotics and resistant bacteria may facilitate the establishment of an environmental reservoir of antibiotic-resistant microbes, promoting their dissemination into agricultural and natural habitats. The main objective of this study was to search for acquired antibiotic resistance determinants in the gut microbiota of wild boar populations living in natural habitats. Gastrointestinal samples of free-living wild boars were collected in the Zemplén Mountains in Hungary and were characterised by culture-based, metagenomic, and molecular microbiological methods. Bioinformatic analysis of the faecal microbiome of a hunted wild boar from Japan was used for comparative studies. Also, shotgun metagenomic sequencing data of two untreated sewage wastewater samples from North Pest (Hungary) from 2016 were analysed by bioinformatic methods. Minimum spanning tree diagrams for seven-gene MLST profiles of 104 E. coli strains isolated in Europe from wild boars and domestic pigs were generated in Enterobase. In the ileum of a diarrhoeic boar, a dominant E. coli O112ab:H2 strain with intermediate resistance to gentamicin, tobramycin, and amikacin was identified, displaying sequence type ST388 and harbouring the EAST1 toxin astA gene. Metagenomic analyses of the colon and rectum digesta revealed the presence of the tetQ, tetW, tetO, and mefA antibiotic resistance genes that were also detected in the gut microbiome of four other wild boars from the mountains. Furthermore, the tetQ and cfxA genes were identified in the faecal microbiome of a hunted wild boar from Japan. The gastrointestinal microbiota of the free-living wild boars examined in this study carried acquired antibiotic resistance determinants that are highly prevalent among domestic livestock populations.

A significant threat to public health is presented by antibiotic-resistant strains of bacteria, selective pressure on which results from antibiotic use. Colistin is an antibiotic commonly used in veterinary medicine, but also one of last resort in human medicine. Since the 2015 discovery in China of the mcr-1 gene encoding colistin resistance in Enterobacteriaceae, other countries have noted its presence. This study was to find the mcr-1 gene prevalence in E. coli isolated from poultry slaughtered in Poland. Cloacal swabs were taken from December 2017 to October 2018 from broiler chickens in three regions. The samples (n = 158) were grouped as flocks treated with colistin sulphate (n = 87) and those not treated (n = 71). Resistance to antimicrobials commonly used in poultry was evaluated by minimum inhibitory concentration. The presence of the mcr-1 gene was confirmed by PCR. Isolates containing the mcr-1 gene were yielded by 11.27% of the samples from not treated flocks and 19.54% of those from treated flocks, but no statistically significant difference in the prevalence of the gene was seen between the groups. The results clearly preclude intensification of selective pressure for colistin resistance due to colistin sulphate treatment because they show that the avian gastrointestinal tract was already inhabited by colistin-resistant E. coli by the time the chickens came to the poultry house.