Virulence-associated genes and antimicrobial resistance among avian pathogenic Escherichia coli from colibacillosis affected broilers in Pakistan.

Avian pathogenic Escherichia coli (APEC) causes colibacillosis that leads to high morbidity and mortality among poultry birds. To date, there is a lack of knowledge about virulence-associated genes (VAGs) and multidrug resistance of APEC isolates from Pakistan. In this study, we determined the VAGs and antibiotic resistance profiles of APEC isolates recovered from colibacillosis affected broilers in Faisalabad region of Pakistan. A total of 84 diseased and dead birds from different local broilers farms were collected and examined for the gross lesions of colibacillosis by conducting postmortem examination. Of these, APEC isolates were recovered from 75 (89.2%) birds. Antibiotic susceptibility tests against 11 antimicrobial agents showed the highest resistance against ampicillin (98.6%) followed by tetracycline (97.3%) and ciprofloxacin (72%). The presence of 11 virulence-associated genes (VAGs) was detected by multiplex polymerase chain reaction (PCR). Of the 75 APEC, 32 (42.6%) harbored > 5 VAGs. Most commonly found genes were increased serum survival (iss; 84%), iron transport (iutA; 74.6%), and colicin V (ColV; 60%). Twenty-two isolates (29.3%) were found to possess a combination of VAGs; iss, tsh, iroN, and iutA, in addition to other VAGs. To the best of our knowledge, this is the first report on the detection of virulence-associated genes and multidrug resistance among APEC isolates in Pakistan. In the future, the strains with the predominant set of VAGs can be used for colibacillosis diagnosis and as a potential vaccine candidate.

Review - Lactic acid bacteria in traditional fermented Asian foods.

Lactic acid bacteria play vital roles in various fermented foods in Asia. This paper reviews many types of the world's lactic acid fermented foods and discusses the beneficial effects of lactic acid fermentation of food. The lactic acid bacteria associated with foods now include species of the genera Carnobacterium, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Tetragenococcus, Vagococcus and Weissella. Lactic acid bacteria (LAB) are involved in many fermentation processes of Asian traditional foods, demonstrating their profound effects on improving food quality and food safety. During the past few decades' interest has arisen in the use of the varied antagonistic activities of LAB to extent the shelf-life of protein-rich products such as meats and fish. This review article outlines the main types of LAB fermentation as well as their typical fermented foods such as idli, kishk, sauerkraut, koumiss, Suan-tsai, stinky tofu, Chinese sausage and kefir. The roles of LAB and the reasons for their common presence are also discussed.

Genomic landscape of multi-drug resistant avian pathogenic Escherichia coli recovered from broilers.

Colibacillosis, a disease caused by avian pathogenic Escherichia coli (APEC), constitutes a substantial burden to the poultry industry worldwide. APEC has been extensively characterized throughout the world, however, less is known about the genetic background of APEC isolates from Pakistan. In this study, a total of 75 E. coli isolates from colibacillosis affected dead broiler birds in Pakistan were subjected to whole genome sequencing followed by in-silico characterization. These isolates were investigated for virulence and resistance genotypes, serotypes, multi-locus sequence types, plasmid replicon types and single nucleotide polymorphism-based core genome phylogeny. Among the APEC isolates investigated, 14 different sequence types were identified with ST117 (16 %), ST2847 (10.7 %) and ST48 (5.3 %) being the most prevalent. Of the 28 different serotypes identified in this study, O1, O2 and O78 serotypes accounted for 25.3 % of the APEC isolates. The most frequently identified virulence-associated genes (VAGs) were increased serum survival gene; iss (100 %), glutamate decarboxylase; gad (92 %) and the siderophore receptor; iroN (81.3 %). According to the previously established definition, 72 % of isolates fell within the highly pathogenic APEC category by possessing a combination of VAGs; iss, iroN, iutA, hlyF and ompT simultaneously. Of the 75 APEC isolates, 89.3 % contained the genes predicted to encode resistance against aminoglycosides, tetracyclines and sulfonamides. Notably, the acquired colistin resistance gene mcr-1 was found in 38.7 % of the APEC isolates. Our findings reveal a diverse genetic background and high virulence and resistance potentials for APEC isolates in Pakistan.

Genomic background of a colistin-resistant and highly virulent MCR-1-positive Escherichia coli ST6395 from a broiler chicken in Pakistan.

The convergence of high virulence and multidrug resistance (MDR) in Gram-negative pathogens circulating at the human-animal interface is a critical public health issue. We hereby report the genomic characteristics and virulent behavior of a colistin-resistant Escherichia coli, serotype ONT:H26, belonging to ST6395, isolated from a healthy broiler in Pakistan. This strain harbored multiple antimicrobial resistance genes, including mcr-1.1 and blaCARB-2, besides cma (colicin M) and astA [heat-stable enterotoxin 1 (EAST1) toxin] virulence genes. In vivo experiments carried out with the Galleria mellonella infection model revealed that MCR-1-positive E. coli ST6395 killed 96.4% of the larvae at 18 hour post-infection. Interplay between resistance and virulence in clinically important pathogens could be a potential threat, representing a serious challenge to global public health.