• Biomedical Science Letters
• /
• v.27 no.2
• /
• pp.45-50
• /
• 2021

Coagulase-negative staphylococci (CoNS) are a typical group of microorganisms, and the recent advances in laboratory technology and medicine has dramatically modified their significance in medical practice. CoNS, which were previously classified as normal bacterial flora, have recently been reported to be associated with serious infectious diseases, such as surgical wound infection or periprosthetic joint infection. Representative CoNS include Staphylococcus epidermidis, S. haemolyticus, and S. saprophyticus, which are known to cause serious problems in biomaterial-based and prosthetic device infections, as well as to cause simple urinary tract infections in sexually active women. Over the last decade, the clinical isolation rate of CoNS has been increasing, and antibiotic resistance has also been occurring. This review aimed to investigate the incidence of CoNS infection and to use the results as basic data for the management of CoNS, with a focus on the isolation rate and antibiotic resistance in clinical surgery.

• Animal Bioscience
• /
• v.34 no.4
• /
• pp.734-742
• /
• 2021

Objective: The present study aimed to investigate the occurrence and species of coagulase-positive staphylococci (CoPS) and coagulase-negative staphylococci (CoNS) in retail pork meat samples collected during nationwide monitoring. The staphylococcal isolates were characterized for antimicrobial and zinc chloride resistance and enterotoxigenic potential. Methods: A total of 260 pre-packaged pork meat samples were collected from 35 retail markets in 8 provinces in Korea for isolation of staphylococci. Antimicrobial and zinc chloride resistance phenotypes, and genes associated with the resistance phenotypes were determined on the isolates. Furthermore, the presence and distribution of 19 staphylococcal enterotoxin (SE) genes and enterotoxin-like genes among the pork-associated staphylococci were determined by multiplex polymerase chain reaction-based assays using the specific primer sets. Results: A total of 29 staphylococcal strains (29/260, 11.1%) were isolated from samples of retail pork meat, 24 (83%) of which were CoNS. The four CoNS species identified were S. saprophyticus (n = 16, 55%), S. sciuri (n = 3, 10%), S. warneri (n = 3, 10%), and S. epidermidis (n = 2, 7%). Among the 29 isolates, four methicillin-resistant CoNS (MR-CoNS; three S. sciuri and one S. epidermidis) and one methicillin-resistant CoPS (MR-CoPS; one S. aureus) were identified. In addition, a relatively high level of tetracycline (TET) resistance (52%) was confirmed in CoNS, along with a predominant distribution of tet(K). The most prevalent SEs were sep (45%), and sen (28%), which were carried by 81% of S. saprophyticus. Conclusion: These findings suggest that CoNS, especially S. saprophyticus strains, in raw pork meat could be a potential risk factor for staphylococcal food poisoning (SFP), and therefore, requires further investigation to elucidate the role of SEls in SFP and virulence of the pathogen. Our results also suggest that CoNS from raw pork meat may act as a source for transmission of antimicrobial resistance genes such as staphylococcal cassette chromosome mec and tet(K).

• Korean Journal of Clinical Laboratory Science
• /
• v.49 no.4
• /
• pp.420-426
• /
• 2017

Methicillin-resistant Staphylococcus (MRS) can be colonized in various body sites and is more frequently isolated in healthcare associated persons. This study aimed to evaluate the contamination rate of MRS in a high school environment, those living with closed life style. Staphylococcus aureus was isolated from only the hands of 2 students among a sample of 28 students, and S. aureus were susceptible to methicillin antibiotics. Coagulase negative Staphylococci (CoNS) were isolated from the hands of 26 students (26/28, 92.9%), and among them, 14 (53.8%) isolates were methicillin-resistant CoNS (MRCoNS). Among the 14 MRCoNS, S. warneri was the most common (8/14, 57%) and susceptible to most $non-{\beta}-lactam$ antibiotics, such as clindamycin, erythromycin, ciprofloxacin, tetracycline, gentamicin, and vancomycin. In a culture of 31 desks, S. aureus was not isolated but CoNS were isolated from 26 desks (26/31, 83.6%), which did not harbor the mecA gene. The other bacteria isolated from the hands and desks were Micrococcus and Bacillus spp. In conclusion, methicillin-resistant S. aureus was not isolated from the hands and desks of high school students. However, the frequency of MRCoNS harboring mecA gene were high in the hands of high school students. Therefore, to prevent and to control the transfer of infection, intensifying preventive education, such as hand washing, and active surveillance systems, such as an investigation of contamination or carrier rate of resistant bacteria are necessary.

• Journal of Veterinary Clinics
• /
• v.34 no.5
• /
• pp.335-340
• /
• 2017

Methicillin-resistant staphylococci (MRS), which are often multi-drug resistant (MDR), are important pathogens in both human and veterinary healthcare. The purpose of this study was to characterize the antimicrobial resistance of MRS isolated from dog ears in Korea. From 827 dog ears, staphylococci were cultured from both ears with otitis externa (n = 161, 41.0%) and healthy ears (n = 135, 31.1%). The prevalence of coagulase-positive staphylococci (CoPS) in ears with otitis externa (58.4%) was significantly higher (p < 0.05) than in healthy ears (28.2%), while the prevalence of coagulase-negative staphylococci (CoNS) in healthy ears (74.8%) was higher (P < 0.05) than in ears with otitis externa (41.6%). Forty-six (35.1%) and 74 (44.8%) CoPS and CoNS isolates, respectively, were determined to be MRS. Antimicrobial resistance in MRS was most frequently observed for penicillin (76.7%), ampicillin (61.7%), kanamycin (61.7%), erythromycin (47.5%), tetracycline (47.5%), and trimethoprim/sulfamethoxazole (46.7%). Overall, the MDR isolates were resistant to significantly more (P < 0.05) antimicrobial agents tested than methicillin-sensitive staphylococci in this study. These results provide therapeutic guidelines for the treatment of otitis externa in dogs from Korean veterinary hospitals, and the significant associated health concern to companion animals and their human contacts.

• Pediatric Infection and Vaccine
• /
• v.29 no.1
• /
• pp.46-53
• /
• 2022

It is challenging to treat ventriculitis with parenteral treatment alone in some cases because of the difficulty involved in maintaining an appropriate level of antibiotics in cerebrospinal fluid (CSF). We report two cases of ventriculitis who did not respond to intravenous (IV) antibiotics but were successfully treated with intraventricular antibiotics using IV agents. The first case was a four-month-old male patient with X-linked hydrocephalus. He showed ventriculitis due to Klebsiella pneumoniae not producing extended-spectrum β-lactamase and susceptible to third-generation cephalosporins and gentamicin, following ventriculoperitoneal (VP) shunt. His condition did not improve during the 47 days of treatment with IV cefotaxime and meropenem. We achieved improvement in clinical presentation and CSF profile after three times of intraventricular gentamicin injection. The patient was discharged from the hospital with antiepileptic drugs. The second case was a six-month-old female patient with a history of neonatal meningitis complicated with hydrocephalus at one month of age, VP shunt at two months of age, followed by a methicillin-resistant coagulase-negative staphylococci (CoNS) shunt infection with ventriculitis after the shunt operation. CoNS ventriculitis recurred four weeks later. We failed to treat intractable methicillin-resistant CoNS ventriculitis with IV vancomycin for ten days, and thus intraventricular antimicrobial treatment was considered. Five times of intraventricular vancomycin administration led to improvement in clinical parameters. There were only neurological sequelae of delayed language development but no other major complications. Patients in these two cases responded well to intraventricular antibiotics, with negative CSF culture results, and were successfully treated for ventriculitis without serious complications.

• Biomedical Science Letters
• /
• v.20 no.2
• /
• pp.77-84
• /
• 2014

Periodic analysis of local epidemiologic data of prevalent pathogens of blood culture can provide clinicians with relevant information to guide empirical antibiotic therapy. In this study, we analyzed a pattern of change of causative microorganisms and antimicrobial resistance at a tertiary medical center in Chungcheong province from 2003 to 2012, retrospectively. Of 70,258 blood specimens cultured, 6,063 (8.6%) were positive. Among the positive isolates, 95.9% were aerobic or facultative anaerobic bacteria, 0.1% were anaerobes, and 3.9% were fungi. Coagulase-negative Staphylococci (CoNS) (32.9%), Escherichia coli (16.7%), Staphylococcus aureus (9.1%), Klebsiella pneumoniae (6.4%), and ${\alpha}$-hemolytic Streptococcus (5.9%) were commonly isolated bacteria, and Candida albicans (1.4%) was the most commonly isolated fungi. Enterococcus faecium progressively increased but Streptococcus pneumoniae, Acinetobacter baumannii and Proteus species gradually decreased over a period of 10 years. The multidrug-resistant microorganisms such as methicillin-resistant S. aureus (MRSA), vancomycin-resistant enterococci (VRE), cefotaxime-resistant E. coli, imipenem-resistant Pseudomonas aeruginosa (IRPA) and imipenem-resistant A. baumannii (IRAB), were significantly increased. Therefore, there is a need for a more strict control of antibiotics and a more updated guideline for the treatment of bloodstream infection.