E. coli is one of the major significant pathogens causing mastitis, the most complex and costly diseases in the dairy industry worldwide. Present study was undertaken to isolate, detect the virulence factors, phylogroup, antimicrobial susceptibility and antimicrobial resistance genes in E. coli from cows with clinical mastitis. A total of 68 milk samples comprising 53 from clinical mastitis and 15 from apparently healthy cattle were collected from four different established dairy farms in Bangladesh. E. coli was isolated from the milk samples and identified by PCR targeting malB gene and sequencing of 16S rRNA gene. E. coli isolates were screened by PCR for the detection of major virulence genes ( stx , eae and cdt ) of diarrheagenic E. coli followed by phylogenetic grouping. Antimicrobial susceptibility of the E. coli isolates was determined by disk diffusion test and E. coli showing resistance was further screened for the presence of antimicrobial resistance genes. E. coli was isolated from 35.8% of the mastitis milk samples but none from the apparently healthy cattle milk. All the E. coli isolates were negative for stx , eae and cdt genes and belonged to the phylogenetic groups A and B1 which comprising of commensal E. coli . Antibiotic sensitivity testing revealed 84.2% (16/19) of the isolates as multidrug resistant. Highest resistance was observed against amoxicillin (94.5%) followed by ampicillin (89.5%) and tetracycline (89.5%). E. coli were found resistant against all the classes of antimicrobials used at the farm level. Tetracycline resistance gene ( tetA ) was detected in 100% of the tetracycline resistant E. coli and bla TEM-1 was present in 38.9% of the E. coli isolates. Findings of this study indicate a potential threat of developing antimicrobial resistance in commensal E. coli and their association with clinical mastitis. Occurrence of multidrug resistant E. coli might be responsible for the failure of antibiotic therapies in clinical mastitis as well as pose potential threat of transmitting and development of antibiotic resistance in human.

Cattle are considered as one of the sources of pathogenic E. coli worldwide. The present study was designed to determine the prevalence and identification of the E. coli isolated from rectal swab of apparently healthy cattle in Mymensingh, Bangladesh. A total of 128 rectal swab samples were assessed by cultural, morphological and biochemical examination followed by Polymerase Chain Reaction (PCR) using primers ECO-1 and ECO-2 that are specific for E. coli 16S rRNA gene. Data obtained from this study were analyzed based on the age, sex, breed and management systems of cattle. This study revealed a 75% prevalence of E. coli in the rectal swab of cattle. Higher prevalence was found in female cattle of unorganized farming systems, and in cattle ≥3 years of age. From this study, it may be concluded that, irrespective of age, sex, breed and management system, E. coli is prevailing in the rectal swab of apparently healthy cattle.

No abstract

The purpose of this study was to investigate the prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-Ec) in retail chicken meats in Japan. Fifty-six domestic and 50 imported (Brazil, n=36; United States, n=8; Thailand, n=6) chicken meat samples were analyzed. The 162 ESBL-Ec included 111 from 43 (77%) domestic samples and 51 from 26 (52%) Brazilian samples. Fifty-three and 30 of 111 and 51 ESBL-Ec from domestic and Brazilian chickens, respectively, were selected for ESBL genotyping. The blaCTX-M (91%), blaTEM (36%) and blaSHV (15%) genes were detected in ESBL-Ec isolated from domestic chickens, whereas blaCTX-M (100%) and blaTEM (20%) were detected in ESBL-Ec isolated from imported chickens. Among the blaCTX-M group, blaCTX-M-2 (45%) and blaCTX-M-1 (34%) were prevalent in domestic chicken isolates, whereas blaCTX-M-2 (53%) and blaCTX-M-8 (43%) were prevalent in imported chicken isolates. Domestic chicken isolates were mostly resistant to tetracycline (83%), followed by streptomycin (70%) and nalidixic acid (62%). Imported chicken isolates were resistant to streptomycin (77%), followed by nalidixic acid (63%) and tetracycline (57%). Notably, extensive multidrug resistance was detected in 60% (32/53) and 70% (21/30) ESBL-Ec from domestic and imported chickens, respectively. Virulence genes associated with diarrheagenic and extra-intestinal pathogenic E. coli were detected in ESBL-Ec isolated from domestic and imported chickens. These data suggest that ESBL-Ec in retail chicken meats could be a potential reservoir for antimicrobial resistance determinants and that some are potentially harmful to humans.

Anthrax is a rapidly fatal infectious disease affecting herbivores and people. In the farm ani¬mals, cattle and sheep are more susceptible, followed by goats and horses, while dwarf pigs and Algerian sheep are relatively resistant. Bacillus anthracis, the causative agent of anthrax, produces spores and persists for decades in the soil, initiating an outbreak through a favorable climate shift. Anthrax is enzootic in many Asian and African countries, and is reported in Australia, some parts of Europe, and America. The clinical courses of this disease in animals are peracute, acute, sub¬acute, and chronic forms. In severely infected cases, the animals are dead without premonitory clinical signs. The blood may fail to clot and can be found in the mouth, nostrils, and anus in the animals that die from anthrax. This bacterium is susceptible to many antibiotics, yet only penicillin and oxytetracycline have the most effective under field conditions. When an outbreak occurs in a defined area, it is necessary to take early steps to break the infection cycle by maintaining strict biosecurity and vaccinating uninfected animals. This disease is still a challenge to farm animal production in many countries. This review intends to give a fair knowledge of the etiology, epi¬demiology, pathogenesis, clinical presentation, diagnosis, treatment, and control of this disease.