• Korean Journal of Veterinary Research
• /
• v.45 no.2
• /
• pp.179-183
• /
• 2005

Epidemiological characteristics of a total of 48 swine herd with diarrhea or a history of diarrhea in Gyeongsang-do between 1999 and 2000 were performed to evaluate the prevalence of Salmonella spp., their serotypes and antibiotic resistance patterns with respect to the different stages of swine production system. A total of 139 Salmonella spp. (21%) were isolated from 662 fecal samples and the overall herd prevalence of Salmonella spp. ranged from 12.5% to 88%. The average prevalence of Salmonella spp. from swine stages of suckling/nursery, grow/finisher and sow stage were 25.7%, 19.2% and 18.4%, respectively. Ten serotypes of Salmonella spp. were identified with a predominance of S. Typhimurium, S. Derby and S. Agona. Twenty-five isolates (18%) were found to be untypable. One hundred and two Salmonella isolates (73.4%) resistant to more than 1 antibiotic were characterized by 24 diverse resistance patterns, and their frequency of antibiotic resistance was highest in grow/finisher stage (83.3%). Resistance to tetracycline (TE; 67.6%), sulfamethoxazole (SU; 46.8%) and streptomycin (ST; 28%) was most common and the most common resistance patterns were TE SU (31.4%), TE (21.6%) and TE SU ST (20.6%) in order.

• Korean Journal of Veterinary Research
• /
• v.45 no.1
• /
• pp.75-83
• /
• 2005

The purpose of this study was to investigate the antibiotic resistance pattern of E. coli and Salmonella spp. isolated from chicken feces. One hundred and forty-seven E. coli isolates showed resistance to tetracycline (95.2%), erythromycin (89.2%), ampicillin (70.1%), streptomycin (59.2%), cephalothin (56.5%), sulfamethoxazole/trimethoprim (53.7%), ciprofloxacin (57.1%), enrofloxacin (59.2%) and norfloxacin (57.1%). The multiple resistance was seen in 144 isolates (97.9%) and the rate of five, six and seven drugs resistance pattern were 20.4%, 18.4% and 16.3%, respectively. Also, the multiple resistance of E. coli to twelve drugs were seen in 1 isolates (0.7%). Fourteen Salmonella spp. showed resistance to ampicillin (50.0%), streptomycin (57.1%), erythromycin (64.3%) and tetracycline (57.1%) and the rate of two and three drugs resistance pattern were 4 isolates (28.6%), respectively. The prevalence of resistant organisms in Korea probably reflects lack of proper antibiotic policy resulting in prolonged and indiscriminate use of antimicrobial agents.

• Food Science and Biotechnology
• /
• v.14 no.2
• /
• pp.216-222
• /
• 2005

This study was performed to determine the antibiotic susceptibility profiles of Salmonella spp., coliforms, Listeria monocytogenes, Staphylococcus aureus and Vibrio spp. isolated from broiler carcasses, aquacultured flounders, hamburgers, and lettuce, which are foods consumed in large quantities in Korea. Salmonella spp. and L. monocytogenes were isolated only from broiler carcasses and Salmonella spp. had a high multidrug resistance rate of 61.1%. Meanwhile, coliforms and S. aureus were isolated from all four foods tested in this experiment. The multidrug resistance rate of coliforms from broiler carcasses was 50%, and that of Vibrio spp. from flounders was 71.4%. The resistance to tetracycline, streptomycin, ampicillin or carbenicillin was common regardless of the kind of food or isolate.

• Microbiology and Biotechnology Letters
• /
• v.48 no.2
• /
• pp.230-235
• /
• 2020

The global evolution of antibiotic resistance has threatened the efficacy of available treatment options with ravaging impacts observed in developing countries. As a result, investigations into the prevalence of antibiotic resistance and the role of plasmids are crucial. In this study, we investigated the presence and distribution of bla_TEM and gyrA genes, plasmid profiles, and the antimicrobial susceptibility pattern of Salmonella strains isolated from raw meat and stool sources across Niger State, Nigeria. Ninety-eight samples, comprising 72 raw meat and 26 stool samples, were screened for Salmonella spp. The antimicrobial susceptibility of Salmonella isolates to 10 commonly used antimicrobial agents was determined using the KirbyBauer disc diffusion method. Isolates were further analyzed for plasmids, in addition to PCR amplification of beta-lactamase (bla_TEM) and gyrA genes. A total of 31 Salmonella spp. were isolated, with 22 from raw meat (70.97%) and 9 from stool (29.03%). Salmonella spp. with multiple resistance patterns to ceftazidime, cefuroxime, ceftriaxone, erythromycin, ampicillin, cloxacillin, and gentamicin were detected. Ofloxacin and ciprofloxacin were found to be the most effective among the antibiotics tested, with 67.7% and 93.5% susceptible isolates, respectively. Nine (29.03%) isolates harbored plasmids with molecular sizes ranging between 6557 bp and 23137 bp. PCR amplification of gyrA was detected in 1 (3.23%) of the 31 isolates while 28 isolates (90.32%) were positive for bla_TEM. This study shows the incidence of antibiotic resistance in Salmonella isolates and the possible role of plasmids; it also highlights the prevalence of ampicillin resistance in this local population.

• Journal of Food Hygiene and Safety
• /
• v.39 no.2
• /
• pp.134-151
• /
• 2024

Salmonella spp. is among the most important water-borne and food-borne pathogens and is one of the most common causes of human gastroenteritis and diarrheal diseases globally. In this study, Salmonella spp. isolated from food, environmental samples, and patients with food poisoning or diarrhea were investigated Salmonella serovars, antibiotic resistance using Vitek2, and genetic characteristics through pulsed-field gel electrophoresis (PFGE). Salmonella spp. of 339 strains, including 26 strains from food or environmental samples and 313 strains from patients, were isolated from Jeju Island of South Korea between 2020 and 2023. The monthly number of isolated Salmonella spp. gradually increased from March, with the highest number being in August. No significant differences in Salmonella spp. isolated from patients according to gender was observed. However, Salmonella spp. was most frequently isolated from people aged 70 years or older and least frequently isolated from those between ages 10 and 19 years. Salmonella spp. isolated from food or environmental samples were distributed among eight different serovars and the main serovars were identified in the order of S. Bareilly (26.9%), S. Rissen (23.1%), and S. Thompson (19.3%). Salmonella spp. isolated from patients were distributed among 27 different serovars and the main serovars were identified in the order of S. Bareilly (31.0%), S. Typhimurium (24.6%), and S. Enteritidis (11.5%). The main cause serovars of Salmonella spp. outbreaks are S. Bareilly, S. Enteritidis, S. Thompson. Antibiotic resistance tests indicated resistance to various antibiotics and some Salmonella spp. exhibited multidrug resistance. Salmonella spp. showed various genetic correlations among the 17 serovars. These results indicate that they can be used as basic data for epidemiological investigations by predicting the appearance of Salmonella spp. and providing a scientific basis.

• Korean Journal of Veterinary Service
• /
• v.23 no.1
• /
• pp.77-91
• /
• 2000

This study was conducted to investigate the antibiotic resistance and plasmid profiles of 58 salmonella spp isolated from mesenteric lymphnodes of slaughter pigs in Kyoungbuk province during the period from September 1997 to June 1998. The results obtained are as follow that all isolates were susceptible to amikacin, gentamicin, ciprofloxacin and enrofloxacin, and the majority of isolates were highly susceptible to norfloxacin, colistin, nalidixic acid and apramycin while they were moderately susceptible to kanamycin, cephalothin, chloramphenicol, ampicillin, trimethoprim and penicillin. The majority of isolates were over 90% resistant rates to lincomycin, sulfadimethoxine, vancomycin, methicillin and erythromycin. The plasmid profiles of 58 salmonella spp are developed 1 to 4 fractions, 0.9 to 29.5 Kb molecular range sizes and U strains (45.5%) were showed plasmid profiles by agarose gel electrophoresis. 5 derby harbored 29.5 Kb and 7 Kb, and S schwarzengrund had 14 Kb and 0.9 Kb harboring sizes. Four of 10 S agona and 2 of 4 S typhimurium were harbored 3.1 Kb and n.5 Kb, respectively. Thirty-five untypable strains are developed variable size fractions its showed small size plasmid profile less than 6 Kb and 22 (62.8%) of them had no detectable plasmids.

• Korean Journal of Veterinary Research
• /
• v.63 no.2
• /
• pp.16.1-16.6
• /
• 2023

Salmonella spp. are pathogens involved in most salmonellosis in rabbits. This study examined Salmonella disease in rabbits raised in Thua Thien Hue, Vietnam. Two hundred and 56 rectal swabs of rabbits were taken, and a carrier rate of 33.98% was found. In addition, all the isolated Salmonella spp. strains were 100% motile; positive for H₂S, catalase, Voges Proskauer, coagulase, citrate, maltose, and dextrose; and negative for indole, methyl red, urease, oxidase, sucrose, and lactose. The Kirby-Bauer method showed that these Salmonella strains were susceptible to doxycycline (93.2%), tetracycline (84.1%), and levofloxacin (65.9%). On the other hand, they were highly resistant to streptomycin (95.5%), ampicillin (93.2%), colistin (40.9%), and gentamicin (34.1%). Furthermore, polymerase chain reaction used to screen for virulence and specific genes of Salmonella strains showed that all Salmonella strains isolated carried InvA, fimA, and Stn.

• Journal of Microbiology and Biotechnology
• /
• v.34 no.5
• /
• pp.1101-1108
• /
• 2024

Earlier studies have validated the isolation of extended-spectrum beta-lactamase-producing Salmonella (ESBL-Sal) strains from food. While poultry is recognized as a reservoir for Salmonella contamination, pertinent data regarding ESBL-Sal remains limited. Consequently, the Ministry of Food and Drug Safety has isolated Salmonella spp. from retail meat and evaluated their antibiotic susceptibility and genetic characteristics via whole-genome sequencing. To further elucidate these aspects, this study investigates the prevalence, antibiotic resistance profiles, genomic characteristics, and homology of ESBL-Sal spp. obtained from livestock-derived products in South Korean retail outlets. A total of 653 Salmonella spp. were isolated from 1,876 meat samples, including 509 beef, 503 pork, 555 chicken, and 309 duck samples. The prevalence rates of Salmonella were 0.0%, 1.4%, 17.5%, and 28.2% in the beef, pork, chicken, and duck samples, respectively. ESBL-Sal was exclusively identified in poultry meat, with a prevalence of 1.4% in the chicken samples (8/555) and 0.3% in the duck samples (1/309). All ESBL-Sal strains carried the bla_CTX-M-1 gene and exhibited resistance to ampicillin, ceftiofur, ceftazidime, nalidixic acid, and tetracycline. Eight ESBL-Sal isolates were identified as S. Enteritidis with sequence type (ST) 11. The major plasmid replicons of the Enteritidis-ST11 strains were IncFIB(S) and IncFII(S), carrying antimicrobial resistance genes (β-lactam, tetracycline, and aminoglycoside) and 166 virulence factor genes. The results of this study provide valuable insights for the surveillance and monitoring of ESBL-Sal in South Korean food chain.

• Journal of Food Hygiene and Safety
• /
• v.39 no.1
• /
• pp.1-8
• /
• 2024

Salmonella is widely prevalent in various environments and often detected in poultry. In this study, we investigated the effect of heat treatment on heat resistance via measuring the minimum inhibitory concentration (MIC) values of antibiotics after 3, 6, and 9 min of acclimatization to mild heat treatment (50℃) against 11 strains of Salmonella spp. Most strains were susceptible to chloramphenicol and their MIC values were maintained or decreased after heat treatment compared to the control. Most control and heat-treated strains showed susceptibility or intermediate resistance to ciprofloxacin. All isolates were susceptible to tetracycline, with the MIC increasing after heat treatment for S. Gaminara BAA 711. In the control, three, two, and six strains were susceptible, intermediate resistance, and resistant to gentamicin, respectively. Among them, S. Heidelberg ATCC 8326 had an intermediate MIC breakpoint of 8 ㎍/mL in the control; however, after 3 and 9 min of heat treatment, the MIC value increased to 16 ㎍/mL, indicating it to be resistant. The results of this study revealed the changes in antibiotic resistance in some of the 11 strains after heat treatment. MIC values of ciprofloxacin increased when S. Montevideo BAA 710 was heat treated for 3 and 6 min. MIC values of gentamicin increased after 3 min of heat treatment for S. Enteritidis 109 D1 and after 3 and 9 minutes of heat treatment for S. Heidelberg ATCC 8326. The MIC value of tetracycline increased when S. Gaminara BAA 711 was heat treated for 6 and 9 min.

• Korean Journal of Veterinary Research
• /
• v.34 no.2
• /
• pp.267-273
• /
• 1994

Feces samples, obtained from zoo animals around Seoul, were examined for the isolation of Salmonella species, bioserotype and drug resistance for the prevention and treatment of salmonellosis, Salmonella spp were isolated 19(4.7%) from 408 samples of zoo animals. The subspecies in 19 Salmonella were all subspecies 1. The serological identification of Salmonella isolated were 31.6% in Sal typhimurium, 26.3% in Sal hadar, 21.1% in Sal muenchen, 15.8% in Sal enteritidis and 5.3% in Sal ayinde. The antibiotic resistance of Salmonella isolated were 13(68.4%) strains. The multiple resistant patterns of antibiotics in Salmonella were 2 drugs- and 3 drugs-resistance 30.8% respectively. The transferred rate of resistance to recipients(E coli ML 1410 $NA^r$) in Salmonella was 38.5%.