• Journal of Veterinary Clinics
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• v.4 no.1
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• pp.409-421
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• 1987

For the epidemiological studies of the respiratory infection from 1,918 heads of adult rabbits from January 1980 to December 1985 at an integrated farm, the causative agents were. Isolated samples 92 from of lungs and nasal discharges, and identified by serological and non-serololgical tests, the loss rates by the infection were also investigatyed, and the antimicrobial sensitivities of the isolates were determined. The results obtained were as fellows : 1. The loss rate by respiratory infection was 11.9% among 1,819 heads which raised and 41.7% among 518 heads which lost by diseases, and the rate increased annually. 2. The loss rate of rabbits in Spring (45.0%), Summer (45.5%) and Winter (53.5%) showed significantly higher (P < 0.01) than that in Autumn(29.1%). 3. The loss rate of Rex (56.3%) showed significantly higher (P<0.05) than New Zealand White (40.7%) and Californian (42.0% ). 4. P. multocida.(37.9%), B. brouchiseptica (16.0%), E. coli (10.6%) and so forth were isolated from 92 samples of lungs and nasal discharges. 5. Sixty fours trains of P. multocida were typed by serological or non-serological tests and their all serotypes were A type (62 strains) except 2 strains of untypable. 6. In antimicrobial sensitivity test for 64 isolates of P. multocida, all the strains tested were highly sensitive to chloramphenicol(95.3%), colistin (95.3%), gentamicin (92.2%), kanamycin (90.6%), neomycin (82.8%) and tetracycline (81.3%), but exhibited low sensitivity to streptomycin (26.6%), and all strains were resistant to lincomycin. 7 Twenty seven isolates of B. brouchiseptica showed higher sensitivity to cephalothin (100%), erythromycin (100% ), gentamicin (100%). trimethoprim+sulfamethoxazole (100%), chloramphenicol(88.9%), kanamycin(88.9%), neomycin (88.9%) and colistin (85.2%), but lower sensitivity to nitrofurantoin (18.5%), penicillin(18.5%). streptomycin(18.5%) and ampicillin (14.8%), and all strains were resistant to lincomycin.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.3
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• pp.155-163
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• 2005

The purpose of this study is to investigate the carrier rate of S. aureus in the community, antibiotic susceptibility patterns of the organism, detection of MRSA and mecA gene in MRSA. Identification and antibiotic resistance patterns of S. aureus and MRSA were done by MicroScan Panels. MRSA strain was confirmed by disk diffusion method using oxacillin disk. The mecA gene in MRSA was detected by PCR. Eighty-four strains (27.4%) of S. aureus were isolated from the nasal specimens of 307 university students in Busan in 2004. Sixty-eight strains (81.9%) of 83 S. aureus were resistant to penicllin, 16 strains(19.3%) to erythromycin, 15 strains (18.1%) to gentamicin, 12 strains (14.5%) to tetracycline, 6 strains (7.2%) to chloramphenicol, 3 strains (3.6%) to ofloxacin, 2 strains (2.4%) to cefepime, clindamycin, imipenem, meropenem, norfloxacin, respectively. One strain (1.2%) was resistant to ciprofloxacin, cefazolin, cefotaxime, cefuroxime, and oxacillin. And all the strains (100%) of 84 S. aureus were susceptible to amoxicilin/K clavulanate, ticarcillin/K clavulanate, trimethoprim/sulfamethoxazole, rifampin, syncroid, teicoplanin, and vancomycin. One strain of 84 S. aureus isolates was methicillin-resistant Staphylococcus aureus (MRSA). The mecA gene was detected from the MRSA strain.

• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.53-60
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• 2019

This study was performed to investigate antimicrobial resistance in bacterial isolates obtained from companion dogs in veterinary hospitals and an animal shelter in Incheon. Drug resistance was examined respectively with the isolates of Escherichia coli, Enterococcus faecalis, and Staphylococcus pseudintermedius. The prevalence of drug resistance was calculated for each bacterial species towards 163 E. coli isolates, 156 E. faecalis isolates, and 86 S. pseudintermedius isolates by using selected antimicrobials. E. coli isolates were highly resistant to ampicillin, ciprofloxacin and tetracycline (47.9%, 28.2% and 28.2%, respectively). E. faecalis isolates were highly resistant to quinupristin-dalfopristin, tetracycline, kanamycin, rifampicin (69.8%, 66.0%, 53.8% and 51.9%, respectively). Higher levels of resistance were detected for ampicillin, penicillin, tetracycline, erythromycin, trimethoprim/sulfamethoxazole, telithromycin in S. pseudintermedius isolates (83.7%~52.6%, respectively). Occurrence of methicillin-resistant S. pseudintermedius (MRSP) was confirmed by oxacillin disc diffusion method, resulted in 23.3% occurrence among the S. pseudintermedius isolates (20/86 strains). The occurrence ratio of multidrug-resistance in the isolates of E. coli, E. faecalis, and S. pseudintermedius was 34.5%, 56.9%, and 67.9%, respectively. In this study, higher levels of antimicrobial drug resistance were observed in bacterial isolates obtained from dogs in Incheon. A regular monitoring and surveillance program should be implemented to prevent the emergence and spread of the drug-resistant bacteria carried in companion dogs.

• Infection and chemotherapy
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• v.50 no.4
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• pp.328-339
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• 2018

Background: Pneumococcal disease is a major cause of morbidity and mortality worldwide, especially in patients with comorbidities and advanced age. This study evaluated trends in epidemiology of adult pneumococcal disease in Crete, Greece, by identifying serotype distribution and antimicrobial resistance of consecutive Streptococcus pneumoniae strains isolated from adults during an 8-year time period (2009-2016) and the indirect effect of the infant pneumococcal higher-valent conjugate vaccines 10-valent pneumococcal conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13). Materials and Methods: Antimicrobial susceptibility was performed by E-test and serotyping by Quellung reaction. Multidrug resistance (MDR) was defined as non-susceptibility to penicillin (PNSP) combined with resistance to ${\geq}2$ non-${\beta}$-lactam antimicrobials. Results: A total of 135 S. pneumoniae strains were isolated from adults during the study period. Twenty-one serotypes were identified with 17F, 15A, 3, 19A, and 11A, being the most common. The coverage rates of PCV10, and PCV13 were 17.8% and 37.8%, respectively. PCV13 serotypes decreased significantly from 68.4% in 2009 to 8.3% in 2016 (P = 0.002). The most important emerging non-PCV13 serotypes were 17F, 15A, and 11A, with 15A being strongly associated with antimicrobial resistance and MDR. Among all study isolates, penicillin-resistant and MDR strains represented 7.4% and 14.1%, respectively. Predominant PNSP serotypes were 19A (21.7%), 11A (17.4%), and 15A (17.4%). Erythromycin, clindamycin, tetracycline, trimethoprim-sulfamethoxazole, and levofloxacin resistant rates were 30.4%, 15.6%, 16.3%, 16.3%, and 1.5%, respectively. Conclusion: Although pneumococcal disease continues to be a health burden in adults in Crete, our study reveals a herd protection effect of the infant pneumococcal higher-valent conjugate vaccination. Surveillance of changes in serotype distribution and antimicrobial resistance among pneumococcal isolates are necessary to guide optimal prevention and treatment strategies.

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.51-62
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• 2022

Lactobacillus rhamnosus SKG34 (LrSKG34), a potential probiotic strain, was successfully isolated from Sumbawa Mare's milk. Our previous studies showed that the strain is resistant to gastrointestinal conditions, possesses antioxidant activity, and lowers blood cholesterol levels. Further clarification of the potential probiotic characteristics and safety assessment are necessary. This study aimed to evaluate the adhesion of LrSKG34 to Caco-2 cell monolayers and its effect on mucosal integrity in vitro. We also examined the LrSKG34 safety profile based on antimicrobial susceptibility testing, haemolytic activity determination, Caco-2 cell monolayer translocation evaluation, and in vivo investigation of the effect of LrSKG34 on the physiology, biochemical markers, and histopathological appearance of major organs in an animal model. LrSKG34 attached to Caco-2 cell monolayers and maintained mucosal integrity in vitro. The typical resistance of lactobacilli to ciprofloxacin, gentamicin, vancomycin, trimethoprim-sulfamethoxazole, and metronidazole was confirmed for LrSKG34. No haemolytic activity was observed on blood agar plates, and no LrSKG34 translocation was observed in Caco-2 cell monolayers. Administration of LrSKG34 to Sprague-Dawley rats did not adversely affect body weight. No abnormalities in hematological parameters, serum biochemistry levels, or histopathological structures of major organs were observed in LrSKG34-treated rats. Collectively, the results implicate LrSKG34 as a promising and potentially safe probiotic candidate for further development.

• Animal Bioscience
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• v.35 no.1
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• pp.138-146
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• 2022

Objective: The objective of the current study was to investigate the influences of conventional (CO) and deep litter (DE) systems on antimicrobial resistance in fecal Escherichia coli (E. coli). Methods: A cross-sectional study was carried out to detect antimicrobial resistance to E. coli in swine fecal samples in CO and DE systems located in western and northeastern Thailand. Individual rectal swab samples were taken only from healthy pigs. A total of 215 individual and healthy pigs were randomly selected for isolation and antimicrobial susceptibility test of E. coli by the disc diffusion method. The test panel included amoxicillin (AMX), colistin, doxycycline (DOX), enrofloxacin, gentamicin (GEN), kanamycin, neomycin (NEO), and trimethoprim-sulfamethoxazole (SXT). Results: There were significant (p<0.05) lower resistance levels for GEN, NEO, and SXT in the DE farms compared to those in the CO farms. There was a lower number of antimicrobial resistance agents (p<0.001) in the DE farms compared to those in the CO farms. This result was consistent with those in western (p<0.01) and northeastern (p<0.01) Thailand. Overall, antibiograms of AMX-SXT and AMX-DOX-SXT were found in the CO (19.09% and 20.91%, respectively) and the DE (16.19% and 24.76%, respectively) farms. No antimicrobial resistance (5.71%) was found and AMX (13.33%) resistant pigs in the DE farms, whereas the pattern of AMX-GEN-SXT (6.36%) and AMX-DOX-GEN-SXT (11.82%) resistant pigs was found in the CO farms. Conclusion: The DE system for pig farming was superior to conventional pig farming by lowering the resistance level of fecal E. coli to GEN, NEO, and SXT, with decreasing the number of antimicrobial resistance agents and inducing a small proportion of pigs to be free from antimicrobial resistance.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.2
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• pp.188-195
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• 2023

Antimicrobial resistance patterns of Escherichia coli strains isolated from 30 seawater samples and 30 Korean rockfish Sebastes schlegelii collected from fish farms off the South Coast of Korea in 2018-2019, were investigated. The isolated E. coli (154 strains) showed the highest antimicrobial resistance to tetracycline (44.8%) followed by chloramphenicol (38.3%), streptomycin (37.6%), and trimethoprim/sulfamethoxazole (35.7%). The antimicrobial resistance rate was higher in E. coli strains isolated from Korean rockfish than those from seawater. Multiple antibiotic resistance (MAR) against at least three antimicrobials (MAR index: ≥0.2) was observed in 35.6% and 79.2% of the seawater and Korean rockfish isolates, respectively. In conclusion, continuous monitoring is required to identify changes in antimicrobial resistance and their correlations in the aquatic environment and products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.626-633
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• 2023

Vibrio spp. are aquatic bacteria that are ubiquitous in warm estuarine and marine environments. Especially, V. vulnificus and V. cholerae are currently known to cause potentially fatal infections in humans. This study investigated the distribution and antibiotic resistance of V. vulnificus and V. cholerae isolated from coastal areas of Gyeongsangnam-do in 2022. A total of 252 samples of water, shellfish and coastal sediment were collected from 7 locations along the coast, and 124 samples of fishery products were collected from markets. Among the 252 samples, forty-four V. vulnificus (11.7%) and fourteen V. cholerae non-O1/non-O139 (3.7%), none of which carried the ctx gene, were isolated. Out of the 124 samples, 6 (4.8%) tested positive for V. vulnificus and V. cholerae was not detected. The isolation rates of V. vulnificus and V. cholerae showed a significant correlation with environmental factors such as seawater temperature and salinity. In an antibiotic resistance test, V. vulnificus was susceptible to amikacin, gentamicin, imipenem trimethoprim/sulfamethoxazole, and ciprofloxacin, but resistant to cefoxitin (100.0%), followed by tetracycline (9.1%). Multidrug resistance was also observed. Continuous monitoring of Vibrio pathogens with water temperature and salinity is expected to help reduce the outbreaks, and rational use of antibiotic agents is needed to prevent the accession of antibiotic-resistant microorganisms in aquatic ecosystems.

• Korean Journal of Veterinary Service
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• v.47 no.1
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• pp.27-33
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• 2024

At the present study, it was aimed to explore the states of antimicrobial resistant Staphylococcus aureus isolates from 1,360 chickens, pigs and cattle carcass (400 chickens, 480 pigs and 480 cattle) in Daegu province from January 2022 to December 2022. Among 1,360 samples, 81 of S. aureus were isolated cattle (1.4%), pigs (7.7%) and chickens (9.2%). In antimicrobial susceptibility test, all of the isolates were demonstrated susceptibility to rifampin. But the isolates were showed resistance other antibiotics in order of tetracycline (62.9%), ciprofloxacin (62.9%), tobramycin (58.0%), gentamicin (51.8%), amikacin (40.7%), penicillin (39.5%), clindamycin (35.8%), enrofloxacin (33.3%), trimethoprim/sulfamethoxazole (30.8%), oxacillin (30.8%), minocycline (29.6%), erythromycin (25.9%), quinupristin/dalfopristin (20.9%), chloramphenicol (12.3%), cefoxitin (9.8%). Among the 81 S. aureus isolates, 25 (30.8%) methicillin-resistant staphylococcus aureus (MRSA) were observed. Seven (28.0%) of 25 MRSA harbored mecA gene. About 96% of MRSA were multidrug resistance to at least 3 more drugs. A continuous monitoring and surveillance program to prevent antimicrobial resistance in livestock products is demanded.

• Journal of agricultural medicine and community health
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• v.30 no.2
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• pp.137-149
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• 2005

Objectives and Methods: This study was performed to investigate the etiologic bacterial, viral and protozoal organisms for the diarrhea from hospitals in Chungnam area from January to December in 2004. Total of 787 fecal samples were collected and examined. Results and Conclusions: In test for enteropathogenic bacteria, total of 79 cases out of 787 samples from hospitals showed positive isolation. Among 79 positive samples, 27 cases were confirmed as Salmonella spp.. 20 cases as pathogenic E. coli, 18 cases as Clostridium perfringens, 6 cases as Staphylococcus aureus, 4 cases as Shigella spp. and 4 cases as Vibrio parahaemolyticus. In test for enteropathogenic virus, 190 cases out of 787 samples from hospitals showed positive reaction. Among 190 samples, 115 cases were confirmed as rotavirus, 55 cases as norovirus, 5 case as astrovirus, 4 case as rotavirus & norovirus, 3 cases as adenovirus, 2 case as rotavirus & astrovirus. In test for enteropathogenic protozoa, 6 cases out of 787 samples from hospitals showed positive result. Among 6 samples, 5 cases were confirmed as Entamoeba histolytica and 1 cases as Giardia lamblia. When we classified the positive results by the age of the patients, the highest isolation rate was noted in a group of age under 10 and over 60 for bacterial, viral and protozoal pathogens. Especially, patient below age of 5 showed high positive rate. When we classified the positive results by the time, pageathogenic bacteria were isolated throughout the year, and the highest frequency was noted in August. On the other hand, pathogenic viruses were detected more frequently during the colder season from December to April. Antimicrobial susceptibility test for the isolated bacteria resulted as follows; Salmonella strains showed high drug resistance rates against ampicillin, chloramphenicol, tetracycline, nalidixic acid, ticarcillin. Shigella strains showed high drug resistance rates against ampicillin, trimethoprim/sulfamethoxazole, chloramphenicol, tetracycline, ampicillin/sulbactam, ticarcillin. Pathogenic E. coli strains showed high drug resistance rates against ampicillin, cephalothin, gentamicin, tetracycline, nalidixic acid, ampicillin/sulbactam, ticarcillin.