• Journal of Veterinary Clinics
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• v.38 no.5
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• pp.225-230
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• 2021

A 4-year-old gelding Thoroughbred racehorse, which had been undergoing antibiotic therapy at a local veterinary clinic, was referred to the KRA veterinary center with a 20-day history of continuous right nasal discharge. Patient's history, endoscopic examination, and radiographic examination revealed primary maxillary sinusitis. Under sedation, surgical intervention was performed to collect samples and remove the accumulated mucopurulent exudate in the sinus. Swab samples were collected from the sinus during surgery for cytology and antimicrobial susceptibility testing. Only one type of bacteria was cultured, and molecular analyses of 16S ribosomal RNA gene sequences identified it as Staphylococcus aureus (S. aureus). The isolate was resistant to multiple antibiotics, which are frequently used in equine practice. Trimethoprim-sulfamethoxazole was chosen based on antibiotic susceptibility test, trephination, and sinus lavage using saline were applied to treat bacterial sinusitis. The clinical signs improved after 1 month and the patient resumed training. This report describes S. aureus isolated from bacterial maxillary sinusitis in a horse and its antibiotic susceptibility.

• Korean Journal of Veterinary Research
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• v.63 no.3
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• pp.29.1-29.5
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• 2023

An adult raccoon dog with extensive, deep, and contaminated wounds on the right hip and multiple fractures was rescued. The open wound was managed daily by debridement and flushing for 3 weeks. Modified active drainage was then performed, and antibiotics administered according to the antibiotic susceptibility test. After 2 weeks, the exudate disappeared and the drain was removed. After monitoring for 1 month, the animal was released in to the wild. This case shows that even if infection remains, rapid wound repair is possible if appropriate antibiotic selection through regular examination and active drainage are combined.

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.147-156
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• 2022

Urinary tract infections (UTIs) are one of the most common infections in different age groups, including children. Bacteria are the main etiological agents of UTIs. The aim of the present study was to isolate, identify, and determine the antibiotic susceptibility of bacteria isolated from children with UTIs from Baghdad, Iraq. Three hundred and two urine samples were collected from children aged 6 months to 12 years. The samples were cultured on blood agar and MacConkey agar. The selected colonies were subjected to biochemical tests and antibiotic susceptibility analysis using the Vitek^® 2 Compact automated microbial identification system. In this sample, 299 bacteria were identified, of which, 267 were gram-negative bacteria, and 32 were gram-positive bacteria. Escherichia coli (56%) was the most commonly isolated gram-negative bacteria, followed by Pseudomonas aeruginosa (14%), Enterobacter spp. (10.48%), Klebsiella pneumoniae (9.36%), Proteus spp. (7.8%), Acinetobacter baumannii (1.5%), and Morganella morganii (0.37%). Enterococcus faecalis (62.5%) was the most commonly detected gram-positive bacteria, followed by Staphylococcus aureus (37.5%). E. coli and P. aeruginosa were the most antibiotic-resistant bacteria. Among the tested antibiotics, meropenem showed 100% sensitivity, followed by imipenem (97.4%), amikacin (91.8%), and tobramycin (83.5%). In contrast, the high frequencies of resistance were observed with cefixime (93.2%), cefotaxime (78.7%), and ceftriaxone/cefotaxime (71.2%). In conclusion, carbapenems and aminoglycosides are highly recommended for the empirical treatment of UTIs, while, Quinolones, penicillins, and cephalosporins are not suggested. Frequent antibiotics susceptibility testing are warranted to determine the resistance pattern of UTI bacteria.

• Journal of fish pathology
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• v.28 no.2
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• pp.71-78
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• 2015

In this study, we conducted to the development of a rapid antimicrobial susceptibility test method using WST-1 which is known to water-soluble tetrazolium salt, in order to rapidly response against bacterial diseases in fish. Eight of antibiotics which are permissioned for marine organism from government were used to rapid antimicrobial susceptibility testing using the WST-1. As a result, a similar tendency was verified compare to conventional antibiotic susceptibility test results. Generally, the antibiotic susceptibility test method required about 3 days (72 hours) for determine the effective antibiotics, however, we have confirmed that the our method using WST-1 was required at least 36 hours in this study. Consequentially, our method will contribute to development of rapid antimicrobial susceptibility testing for bacterial diseases in fish.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.685-689
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• 2000

Due to the uncultivable nature of Mycobacterium leprae in vitro, the fast, easy, and accurate measurement of the antimicrobial drug susceptibility of this microbe has been difficult. Conventional methods for such testing are subjective, cumbersome, and expensive in some cases. Here, the utility of a reverse transcriptase-PCR (RT-PCR)-based assay for testing was examined and compared with a Buddmeyer-type radiorespirometric assay. The susceptibility of M. leprae to rifampin was determined by probing the presence of M.leprae-specific 18 kDa gene mRNA in M. leprae-infected IC-21 macrophage cells after drug treatment. The results showed that, as the refampin concentration was increased, the 360-bp cDNA products generated by the RT-PCR-based assay decreased in a dose-dependent manner as in the drug susceptibility observed in the Buddmeyer-type assay. The drug susceptibility testing of M. leprae by the RT-PCR based assay was found to be not only faster but also nearly $10^4$-fold more sensitive than the Buddmeyer-type assay. Moreover, it was also found that, unlike the RT-PCR based assay, the same testing by a DNA-PCR resulted in no differences in the 360-bp signal, regardless of the rifampin concentrations used. Accordingly, these results demonstrated that the drug susceptibility of M. leprae can be determined effectively by an RT-PCR-based assay, thereby providing a new, fast, and sensitive testing method.

• Korean Journal of Clinical Laboratory Science
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• v.45 no.1
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• pp.21-25
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• 2013

Acinetobacter baumannii is an aerobic, gram-negative and glucose-non-fermenting bacterium, which has emerged as a serious opportunistic pathogen. Many clinical microbiology laboratories use the Vitek 2 system for the routine antimicrobial susceptibility testing process, including testing on A. baumannii isolates. However, in case of amikacin, it is now recommended to perform additional antimicrobial susceptibility testing for A. baumannii strains due to the relatively lower minimum inhibitory concentration (MIC) in the Vitek 2 system compared to conventional reference methods. In our study, we assessed MIC for amikacin susceptibility testing of A. baumannii isolates in the Vitek 2 system, the agar dilution, Etest, and disk diffusion method. We collected 40 gentamicin-resistant, A. baumannii strains (amikacin MIC by Vitek 2:${\leq}2{\mu}g/mL$, 2 isolates; $4{\mu}g/mL$, 34 isolates; $8{\mu}g/mL$, 4 isolates) from a University hospital and compared the Vitek 2 system to other reference methods for testing susceptibility to amikacin. The Vitek 2 system showed major errors in all of the 40 isolates, yielding a low MIC. The results of our study strongly suggested that the Vitek 2 system was not a reliable method to test the MICs of gentamicin; ranging from ${\geq}16{\mu}g/mL$ for amikacin susceptibility. Other tests, such as agar dilution, Etest, or disk diffusion methods, should be paralleled to determine the MIC of amikacin in A. baumannii.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.1
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• pp.54-59
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• 1996

Erwinia carotovora subsp. Carotovora (Ecc), a pathogen of tobacco hollow stalk disease, was isolated for testing susceptibility to streptomycin from diseased plants in burley tobacco growing area. Of 157 isolates tested, 17 isolates (108%) were resistant to the antibiotic at the antibiotic from field soils, which streptomycin had been used continuously for three years for control of the disease was three times higher than those of non-used. There was no difference in virulence and generation time between streptomycin-sensitive and resistant strains.

• Korean Journal of Clinical Laboratory Science
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• v.46 no.4
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• pp.136-139
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• 2014

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the severe nosocomial infectious agents. The traditional diagnostic methods including biochemical test, antibiotic susceptibility test and PCR amplification are time consuming and require much work. The Surface enhanced Raman spectroscopy (SERS) biosensor is a rapid and powerful tool for analyzing the chemical composition within a single living cell. To identify the biochemical and genetic characterization of clinical MRSA, all isolates from patients were performed with VITEK2 gram positive (GP) bacterial identification and Antibiotic Susceptibility Testing (AST). Virulence genes of MRSA also were identified by DNA based PCR using specific primers. All isolates, which were placed on a gold coated nanochip, were analyzed by a confocal Raman microscopy system. All isolates were identified as S. aureus by biochemical tests. MRSA, which exhibited antibiotic resistance, demonstrated to be positive gene expression of both femA and mecA. Furthermore, Raman shift of S. aureus and MRSA (n=20) was perfectly distinguished by a confocal Raman microscopy system. This novel technique explained that a SERS based confocal Raman microscopy system can selectively isolate MRSA from non-MRSA. The study recommends the SERS technique as a rapid and sensitive method to detect antibiotic resistant S. aureus in a single cell level.

• Pediatric Infection and Vaccine
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• v.27 no.3
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• pp.147-157
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• 2020

Purpose: We investigated the trend of antibiotic susceptibility of Haemophilus influenzae over 5 consecutive years. Methods: We analyzed the antibiotic susceptibility of H. influenzae isolated from children aged <18 years, who were admitted to the Asan Medical Center Children's Hospital from March 2014 to April 2019. Antibiotic susceptibility of H. influenzae was determined by the disk diffusion test according to the European Committee on Antimicrobial Susceptibility Testing guidelines. Results: Excluding duplicates, 69 isolates were obtained over the past 5 years. The median age of the patients was 5 years (range, 2.8-8.6 years). The antibiotic susceptibility patterns were as follows: ampicillin (AMP)-susceptible/amoxicillin-clavulanate (AMC)-susceptible (AS/ACS; n=15 [21.7%]), AMP-resistant/AMC-susceptible (AR/ACS; n=21 [30.4%]), and AMP-resistant/AMC-resistant (AR/ACR; n=33 [47.8%]). The prevalence of isolates with AR/ACR phenotype tended to increase from 42.1% in 2014-2015 to 54.5% in 2018-2019 (P=0.342). Compared to 2014-2015, the resistance rates to cefuroxime and ceftriaxone in 2018-2019 increased from 31.6% to 77.3% and from 0.0% to 59.1%, respectively (P=0.003 and P<0.001, respectively). Conclusions: Over the last 5 years, H. influenzae isolates with AR/ACR phenotype and ceftriaxone resistance were frequently observed at our institute. The incidence of resistance to cefuroxime and ceftriaxone has increased significantly.

• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.668-679
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• 2023

Edwardsiella tarda is one of the most significant fish pathogens, causes edwardsiellosis in a variety of freshwater fish species, and its antibiotic resistance against multiple drugs has made it a health risk worldwide. In this study, we aimed to investigate the antibiotic resistance (ABR) genes of E. tarda and establish its antibiotic susceptibility. Thus, 540 fish (299 Oreochromis niloticus, 138 O. mossambicus, and 103 O. aureus) were collected randomly from twelve fish farms in three districts of Punjab in Pakistan. E. tarda was recovered from 147 fish showing symptoms of exophthalmia, hemorrhages, skin depigmentation, ascites, and bacteria-filled nodules in enlarged liver and kidney. Antimicrobial susceptibility testing proved chloramphenicol, ciprofloxacin, and streptomycin effective, but amoxicillin, erythromycin, and flumequine ineffective in controlling edwardsiellosis. Maximum occurrence of qnrA, blaTEM, and sul3 genes of E. tarda was detected in 45% in the liver, 58%, and 42% respectively in the intestine; 46.5%, 67.2%, and 55.9% respectively in O. niloticus; 24%, 36%, and 23% respectively in summer with respect to fish organs, species, and season, respectively. Motility, H₂S, indole, methyl red, and glucose tests gave positive results. Overall, E. tarda infected 27.2% of fish, which ultimately caused 7.69% mortality. The Chi-squared test of independence showed a significant difference in the occurrence of ABR genes of E. tarda with respect to sampling sites. In conclusion, the misuse of antibacterial agents has led to the emergence of ABR genes in E. tarda, which in association with high temperatures cause multiple abnormalities in infected fish and ultimately resulting in massive mortality.