Multidrug-Resistant Salmonella Species and Their Mobile Genetic Elements from Poultry Farm Environments in Malaysia

Abstract

The prevalence and persistent outbreaks of multidrug-resistant (MDR) Salmonella in low-income countries have received growing attention among the public and scientific community. Notably, the excessive use of antibiotics in chicken feed for the purpose of treatment or as prophylaxis in the poultry industry have led to a rising rate of antimicrobial resistance. Therefore, this study aimed to determine the presence of antimicrobial-resistant Salmonella species and its mobile genetic elements from soil and effluent samples of 33 randomly selected poultry farms in Selangor, Malaysia. Salmonella species were isolated on selective media (CHROMagar™ Salmonella). VITEK® 2 system was used to identify the isolates and their antimicrobial susceptibility. Subsequently, eight isolates were subjected to the whole genome sequencing (WGS). Based on the results, Salmonella spp. was detected in 38.1% (24/63) of samples, with the highest resistance to ampicillin (62.5%), followed by ampicillin/sulbactam (50.0%) and ciprofloxacin (45.8%). Meanwhile, the identified serovars were Salmonella enterica subspecies enterica serovar Weltevreden (S. Weltevreden), S. Jedburgh, and S. Brancaster. The most prevalent resistance genes detected include qnrS1, blaTEM-176, dfrA14, and tet(A). The IncX1 plasmid, with encoded resistance genes, was also detected in four isolates. Furthermore, mutations in the quinolone resistant-determining regions (QRDR) were discovered, specifically in the gyrA, gyrB, and parC genes. In short, surveillance such as continuous monitoring of antimicrobial resistance and emerging trends in resistance patterns through farm environmental samples could provide information to formulate public health interventions for effective infection prevention and disease control.

Serovars, Virulence and Antimicrobial Resistance Genes of Non-Typhoidal Salmonella Strains from Dairy Systems in Mexico

“…Furthermore, in 2020, Wang and colleagues reported that 50% of the isolated Salmonella demonstrated multi-drug resistance in adult dairy cows [41]. In another study conducted in poultry farms in Malaysia, a high resistance level was reported against ampicillin and ciprofloxacin (62.5 and 45.8%); this could indicate its misuse in the agricultural sector [42].…”

A Retrospective Analysis of Salmonella Isolates across 11 Animal Species (1982–1999) Led to the First Identification of Chromosomally Encoded blaSCO-1 in the USA

“…Salmonella , a Gram-negative Enterobacteriaceae family member, stands as a predominant etiological agent of gastroenteritis [ 1 ]. Non-typhoidal Salmonella (NTS) , an extensive diversity within the Salmonella genus, which is evidenced by the documentation of more than 2600 serovars, is the most common enteric pathogen in animals and humans [ 2 ].…”

“…This poses a substantial and persistent threat to public health and is estimated to cause about 150 million illnesses and 60,000 deaths globally yearly [ 3 ]. These different NTS serovars are prevalent across diverse animal hosts, emphasizing the critical intersection between animal and human health [ 1 ].…”