Detection and characterization of multidrug‐resistant Salmonella enterica serovar Infantis as an emerging threat in poultry farms of Faisalabad, Pakistan

Abstract

Aims The aim of this study was the molecular identification of Salmonella enterica serovar Infantis (S. Infantis) isolated from poultry samples and their antimicrobial resistance and virulence profiling. Methods and Results A total of 149 isolates, belonging to genus Salmonella, originally isolated from 340 suspected poultry post mortem specimens reported by us earlier were preliminary identified as Salmonella by biochemical methods and confirmed by polymerase chain reaction targeting genus‐specific gene invA. Targeting serovar‐specific gene fragment (fljB) resulted in confirmation of 54 isolates as S. Infantis which were further confirmed by sequencing of 16S RNA and fljB genes. Swimming and swarming motilities were detected in 98·1 and 11·1% isolates respectively. Phenotypic disc diffusion assay against 23 antimicrobial agents showed the highest resistance against pefloxacin (PEF) (94·4%), chloramphenicol (83·3%) and imipenem (77·7%) while 5·3% isolates showed extended‐spectrum β‐lactamase production. Fifty‐nine genes reported for antimicrobial resistance and 12 for conferring virulence were targeted. The most prevalent resistance gene for aminoglycosides was aadA (42·3%), for quinolone resistance determining region parE (62·5%), for penicillin's Int1 (62·9%), for chloramphenicol cat3 (66·1%) and for beta‐lactams blaTEM‐1 (44·4%). Among efflux pump coding genes, armA showed highest (74·2%) prevalence and for virulence, a high prevalence of SopE (89·2%) showed the zoonotic potential of the isolates. The activity of efflux pumps was detected through Ethidium Bromide‐agar method. Conclusions Poultry could act as reservoirs of multidrug resistance Salmonella. Significance and Impact of the Study We firstly report the prevalence and molecular characterization of virulence/drug resistance in S. Infantis from this region and the results may contribute to designing precisely targeted therapy. This study has also highlighted the possible emergence of S. Infantis with zoonotic potential.

Antimicrobial Resistance Profile andmcr-1Gene Detection inSalmonellaIsolates from Poultry in Bangladesh: Molecular and Bioinformatics Characterization

“…The present study represented that, 100% of the mcr-1 positive isolates were MDR. Similar findings were reported on MDR in Salmonella isolates from Bangladesh and different parts of the world (29, 67–72). Due to the indiscriminate victimization of antimicrobial agents, MDR strains may apparently be occurred with high incidence in this area which is a serious concern for veterinary medicine and also for human health since direct transmission of resistant isolates from animals to humans has been confirmed (73).…”

“…Salmonella isolates were confirmed by morphological (Gram’s stain), cultural (MacConkey, XLD and S-S agar media) and biochemical (catalase, indole and TSI agar slants test) characteristics as previously described (29). A total of 82 Salmonella isolates were differentiated and confirmed following their morphological and biochemical properties.…”

“…For Salmonella specific pre-enrichment, culture were further transferred to Modified Semi-solid Rappaport Vassiliadis (MSRV; Hi Media, India) and Tetrathionate Broth (TTB; Hi Media, India) consecutively and incubated at 42°C for 24 h. Following enrichment, a loop of enriched broth was initially streaked on Xylose-Lysine-Desoxycholate (XLD; Hi Media, India) agar and colonies (single pinkish) were streaked on Salmonella-Shigella (SS) agar, incubated at 37°C for 24 h. Salmonella colonies were identified by physical and biochemical properties using Gram’s stain, catalase and indole tests as previously described (Dashti et al, 2009; Sobur et al, 2019). For further confirmation, 4-6 suspected Salmonella colonies from each samples were tested biochemically by dilution streaking and stab onto Triple Sugar Iron (TSI) agar (Merck, Germany) and incubation at 37°C for 16-24 h (28, 29).…”

Phenotypic and Genotypic Characterization of Virulence Factors and Susceptibility to Antibiotics in Salmonella Infantis Strains Isolated from Chicken Meat: First Findings in Chile

“…Only three strains of S. Enteritidis were isolated from the 361 samples of chicken meat, suggesting that the emergence of S. Infantis is replacing S. Enteritidis in the chicken-producing chain in Chile. The emergence of the S. Infantis serotype has been described in European countries and the United States [ 4 , 41 , 42 , 43 , 44 ]. In South America, it has also been described in Ecuador [ 45 ] and Peru [ 46 ].…”

An Investigation of Antibacterial Resistance Patterns in Isolated Bacteria from Contaminated Water Samples in Poultry Slaughterhouses

“…Recent studies have reported the emergence of multiple resistance patterns and an increase in the number of resistant bacteria (Wajid et al, 2019). Among resistant bacteria, the Enterobacteriaceae family showed the highest rate of antibiotic resistance.…”