AN IMPROVED METHOD FOR RAPID ISOLATION OF SALMONELLA AGAINST PROTEUS IN CHICKEN CARCASSES

Abstract

An improved method was developed for the rapid isolation and identification of Salmonella in chicken carcasses. Considering the heavy presence of Proteus mirabilis in the poultry‐production environment, we investigated combinations of selective bacterial growth media that promote the growth of Salmonella but inhibit that of P. mirabilis. The improved method was evaluated using standard methods described in the Bacteriological Analytical Manual (BAM) by the U.S. Food and Drug Administration (FDA), and the Microbiology Laboratory Guidebook published by the U.S. Department of Agriculture Food Safety Inspection Service (USDA/FSIS). A total of 44 chicken carcasses were analyzed for Salmonella using the three methods. The FDA/BAM method showed a poor sensitivity and specificity, especially when the tetrathionate (TT) broth was applied. The improved method offered an excellent specificity (>95%) and shortened the time of isolation and identification from 4 to 5 days to less than 3 days, consequently reducing the costs.

Antibiotic Susceptibility and Molecular Screening of Class I Integron in Salmonella Isolates Recovered from Retail Raw Chicken Carcasses in China

“…Detailed information on sample collection, Salmonella isolation, and identification were as previously described. 23,24 Antimicrobial susceptibility test All Salmonella isolates were tested for their susceptibility to antimicrobials. The minimum inhibitory concentrations (MICs) of the antimicrobial agents were determined by the agar dilution method using Mueller-Hinton agar (Beijing Land Bridge Technology Co Ltd., Beijing, China) according to the guidelines recommended by the Clinical and Laboratory Standards Institute (CLSI).…”

Antibiotic Resistance inSalmonellafrom Retail Foods of Animal Origin and Its Association with Disinfectant and Heavy Metal Resistance

“…The methods described by the United States Department of Agriculture Food Safety and Inspection Service were used to isolate Salmonella from retail foods of animal origin. 30 Briefly, 25 g portions of the products were used for culturing. Each sample was placed in separate sterile Erlenmeyer flasks with 225 ml buffered peptone water and incubated at 37°C in a water bath with shaking at 120 rpm for 6 h. After pre-enrichment, 10 and 1 ml of pre-enriched rinses were transferred to 100 ml each of the tetrathionate (TT; Beijing Land Bridge Technology Co., Ltd., Beijing, China) and Rappaport-Vassiliadis (RV; Beijing Land Bridge Technology Co., Ltd.) broths, respectively, and incubated at 42°C in a water bath with shaking at 160 rpm for 24 h. One loopful of overnight TT broth culture was streaked onto xylose lysine tergitol agar plates (Beijing Land Bridge Technology Co., Ltd.), whereas the RV broth was streaked onto agar of xylose lysine deoxycholate (Beijing Land Bridge Technology Co., Ltd.) and incubated at 37°C for 24 h.…”

“…Three presumptive Salmonella colonies from each plate were inoculated onto triple sugar iron (Beijing Land Bridge Technology Co., Ltd.) and urea agar slants (Beijing Land Bridge Technology Co., Ltd.). 30 After 24 h of incubation at 35°C, isolates with typical Salmonella phenotypes were confirmed by polymerase chain reaction (PCR). The PCR assays for identification of Salmonella were described previously.…”

“…The PCR assays for identification of Salmonella were described previously. 30 A 284 bp PCR product targeting invA was amplified using the primers invA 139 (5¢-GTGAAATTATCGCCA CGTTCGGGCAA-3¢) and invA 141 (5¢-TCATCGCACCGT CAAAGGAACC-3¢). Amplicons were sequenced by Shanghai Sangon Bioengineering Co., Ltd. Nucleotide sequences were analyzed using BLAST software, which is available at the National Center for Biotechnology Information web-site (www.ncbi.nlm.nih.gov).…”

Nanogold for In Vitro Inhibition of Salmonella Strains

“…Sugar-Iron (TSI) and Thiosulfate-Citrate-Bile Salts-Sucrose (TCBS). The Salmonella strains were cultured in nutrient media and were ascertained by turbidity and growth of circular, smooth, opaque, and translucent colonies in nutrient agar plates as reported by the authors [43,49]. In the TSI slants shown in Figure 1, the organism produced black colonies at the center due to the production of hydrogen sulfide gas.…”