Staphylococcus Species in the Dental and Medical Environment

Staphylococcus species are one of prevalent pathogens found in hospitals. Microbes that are a primary cause of nosocomial infection were isolated from a dental and medical environment it may assist the reader to explain what this is and how it differs from the 'dental health care providers and ward health care providers'. To investigate the distribution of staphylococcus species in this environment, we used vitek II to measure drug sensitivity, and further performed biochemical testing. The isolation rate of staphylococcus species from the dental and medical environment was 100% but from dental health care providers and ward health care providers were 44.4% and 33.3%, respectively. In the analyses, staphylococcus species showed resistance to diffusion of cefoxitin and oxacillin discs. These staphylococci may be sufficiently positive for the mecA gene. Our results suggest that staphylococci might be an important cause of nosocomial infection in the dental clinic.

The Prevalence, Genotype and Antimicrobial Susceptibility of High- and Low-Level Mupirocin Resistant Methicillin-Resistant Staphylococcus aureus

BACKGROUND: Mupirocin has been used for the treatment of skin infections and eradication of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA). The increased use of this antibiotic has been accompanied by outbreaks of MRSA that are resistant to mupirocin. OBJECTIVE: This study aims to determine the prevalence, genotype and antimicrobial susceptibility of mupirocin-resistant MRSA from 4 Korean hospitals. METHODS: A total 193 MRSA clinical isolates were collected from four university hospitals. Antimicrobial susceptibility tests, including mupirocin, and pulsed-field gel electrophoresis (PFGE) pattern analysis were performed. RESULTS: Overall, 27 of the 193 (14.1%) MRSA isolates were resistant to mupirocin. All of the (A) hospital isolates showed high-level (HL) mupirocin resistance and the low-level (LL) mupirocin resistant strains were from three other hospitals. The PFGE patterns of 16 mupirocin-resistant isolates were divided into 5 clusters (1-5), and the nine HL mupirocin-resistant isolates belonged to cluster 1. Both the HL and LL mupirocin-resistant MRSA isolates were susceptible to vancomycin and rifampin, but they were resistant to ciprofloxacin, clindamycin and tetracycline. The erythromycin and fusidic acid resistance rates were different between the HL and LL resistant isolates. CONCLUSION: HL mupirocin-resistant isolates that could transfer this resistance to other bacteria were detected and these isolates were clonally related. The emergence of mupirocin resistant isolates emphasizes the importance of using antibiotics judiciously and carefully monitoring the prevalence of mupirocin resistance.

Isolation and Antimicrobial Susceptibility of Mupirocin-Resistant and Methicillin-Resistant Staphylococcus aureus from Clinical Samples

Resistance to mupirocin in methicillin-resistant Staphylococcus aureus (MRSA) have increased with wide use of mupirocin in many countries, but the prevalence in Korea is not well-known. The aim of this study was to determine the prevalence, antimicrobial susceptibility, and clonality of mupirocin-resistant (MUP-R) isolates from three Korean hospitals. A total of 175 MRSA isolates were collected from three university hospitals in 2009-2010. Antimicrobial susceptibility was tested by the disk diffusion and the agar dilution methods. femA, mecA and mupA genes were detected by polymerase chain reactions. Pulsed-filed gel electrophoresis (PFGE) pattern of genomic DNA was determined after digestion with SmaI. Overall, 12 among the 175 MRSA isolates were resistant to mupirocin, with prevalence ranging from 0 to 10% depending on hospitals. Three high-level (HL) and nine low-level (LL) MUR-R isolates were obtained from two hospitals. All MUP-R isolates were susceptible to rifampin and vancomycin, but were resistant to ciprofloxacin, clindamycin, and erythromycin. Eight LL and one HL MUP-R isolates were also resistant to fusidic acid. PFGE analysis showed three HL MUP-R isolates belonged to arbitrary cluster 3, 5 and 6 with 60~90% similarity compared to LL MUP-R isolates. In conclusion, the HL resistance to mupirocin was detected in two hospitals, but HL MUP-R isolates were clonally not related.

Prevalence and Antimicrobial Susceptibility of Campylobacter coli Isolates from Swine

Swine is a common source of Campylobacter coli human gastroenteritis, for the treatment of which erythromycin and fluoroquinolones are recommended. The prevalence of antimicrobial-resistant C. coli differs significantly depending on countries. We investigated the prevalence of C. coli in swine from a farm in Buan-gun, Korea in 2010, and determined antimicrobial susceptibility of the isolates. Rectal swab specimens were used to inoculate Campylobacter Preston media and incubated microaerophilically at 42degrees C for 48 h. The species were identified by phenotypic tests and by detecting hipO and glyA genes. PCR was used to detect mutations of A2074C in 23S rRNA gene, and quinolone resistance-determining region (QRDR) of gyrA, which are associated with high level resistance to erythromycin, and with ciprofloxacin, respectively. Antimicrobial susceptibility was determined by the disk diffusion and agar dilution tests. Of the 100 specimens, 55 (55%) yielded C. coli, and 23 of them (41.8%) had A2074G mutation. A2074G mutated isolates showed the lowest MIC90 of imipenem, while those of ampicillin and clindamycin were relatively low. The majority of both A2074G mutation-positive and -negative isolate were susceptible to ampicillin, cefotaxime, and chloramphenicol. All isolates were resistant to ciprofloxacin, and had mutation in QRDR of gyrA. In conclusion, C. coli was detected in 55% of swine, and A2074G mutation was detected in 41.8% of the isolates. All isolates had gyrA mutation-mediated ciprofloxacin resistance.

Pattern of Methicillin-resistant Staphylococcus aureus in Dental and Medical Environments

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most prevalent pathogens in hospitals. To investigate cross contamination by this bacterium in both dental and medical settings, the pathogens that cause acute pyogenic infection and one of the major microbes responsible for nosocomial infection were isolated from health care providers, nurses and patients. We used VITEK II to measure drug sensitivity, and we further performed biochemical testing, coagulase serotype testing and pulse-field gel electrophoresis (PFGE) for isolated MRSA colonies. The isolation rate of Staphylococcus aureus from nasal swabs was 75.0% from dental health care providers and 18.8% from the medical health care providers. A total of 10 MRSA strains were isolated from 40 health care providers and 2 patients and the prevalent coagulase serotype from patients and health care providers was VII. The antimicrobial drug resistance and partial PFGE types of the isolated MRSA strains showed a similar pattern. These results suggest that MRSA may be one of the principal causes of nosocomial infection in dental and medical hospitals.

Monitoring of Methicillin-resistant Staphylococcus aureus in Nasal Swabs Obtained from Dental Clinic Healthcare Providers and Medical Environment Nurses

The aims of this study were to investigate the nosocomial infection route of methicillin-resistant Staphylococcus aureus (MRSA) and explore preventative methods for this pathogen that involve blocking its dispersion. We cultured MRSA from nasal cavity swabs collected between June and July 2008 that we obtained from eight dental healthcare providers, 32 nurses and the sputum specimens of two patients from our hospital. In addition, we used VITEK 2 equipment to measure drug sensitivity, and we further performed biochemical testing and pulse-field gel electrophoresis (PFGE) to isolate MRSA colonies. The incidence of these bacteria on the nasal swabs was 25.0% from dental clinic healthcare providers, 13.6% from the internal medicine ward nurses and 30.0% from intensive care unit nurses. Moreover, MRSA was detectable in sputum specimens of ward patients. The antimicrobial agents resistance and partial PFGE types of MRSA showed a similar pattern. We suggest from these analyses that nasal cavity infection by MRSA could occur by cross contamination between healthcare providers and patients which underscores the importance of stringent MRSA management practices.

Genotype, Coagulase Type and Antimicrobial Susceptibility of Methicillin-Resistant Staphylococcus aureus Isolated from Dermatology Patients and Healthy Individuals in Korea

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most prevalent dermatology pathogens in hospitals and increasingly recognized in communities. We determined PFGE pattern of SmaI-restricted genomic DNA, coagulase type, and antimicrobial susceptibility of MRSA isolated in 2008 from dermatology inpatients and healthy hospital employees in A Hospital and from primary school children in Iksan city, Korea. Overall, the isolation rate of MRSA was 3.8% from the 788 normal persons: 4.9% from hospital employees and 1.1% from primary school children. MRSA was isolated in six of 13 (46.2%) family members of four school children with MRSA. The most prevalent coagulase serotype was II from patients and V from healthy individuals. Ten of twenty and six of twenty MRSA isolates from patients and from healthy personnel, respectively, had identical PFGE patterns, suggesting that these are originated from identical clones. Against MRSA from patients, only vancomycin was the most active (MIC range or =90% to amikacin, clindamycin, ciprofloxacin, erythromycin, fusidic acid, gentamicin and tetracycline. In conclusion, the MRSA carriage rates of healthy hospital workers were relatively high, 2.3~7.7%, depending on groups. Family members of a few primary school children with MRSA showed a high carriage rate, suggesting that intrafamily transmission occurred. MRSAs isolated from dermatology inpatients were relatively more resistant to various antimicrobial agents, including mupirocin, but all isolates were susceptibility to vancomycin.

Determination of the Biogroup of Vibrio vulnificus Isolates from Patients and Oysters in Korea / 대한피부과학회지

BACKGROUND: Vibrio vulnificus are divided into 3 biogroups based on their biochemical and serological properties and the existence of eel virulence. Only a few studies can be found on the biogroups of V. vulnificus in other countries, and no such studies have been done in Korea. OBJECTIVE: The aim of this study was to determine the presence of biogroups other than biogroup 1 among the V. vulnificus isolated from septic patients and from oysters in Korea. METHODS: A total of 103 isolates (53 from septic patients and 50 from oyster) were used. The API 20E system was used to confirm identification of the V. vulnificus. Conventional biochemical tests and vvA gene detection by polymerase chain reaction (PCR) were used to determine the biogroups. RESULTS: The clinical and oyster isolates showed results similar to the biochemical tests. All of the clinical and oyster isolates showed the biochemical pattern of biogroup 1. The vvhA gene was detected in all of the isolates. CONCLUSION: All of the V. vulnificus isolates from the septic patients and oysters in Korea belong to biogroup 1.

Improvement of the Positive Culture Rate Using New Enriched Broth in Cellulitis / 대한피부과학회지

BACKGROUND: Staphylococcus aureus and Group A beta-hemolytic Streptococci are the etiologic agents most commonly associated with cellulitis, but many other bacteria have also been shown to cause this condition. The positive bacterial culture rate is the most important factor in the treatment of cellulitis. However, the positive bacterial culture rate in the commonly used media, tends to be quite low. OBJECTIVE: The principal objective of this study was to improve the positive culture rate in cellulitis patients by using a new enriched broth. METHODS: Brewer modified thioglycollate medium (BTM) and Columbia broth (CB), both of which are widely utilized in clinical bacteriology for enriched growth, were compared with several novel enriched broths. These new enriched broths were mixtures of BTM-CB broth and added growth supplement factors. They included BTM-CB (BC), Modified BTM-CB (MBC) and supplement VX-BTM-CB (VXBC). MBC media included several growth supplements, such as hemin, vitamin K1, VX supplement, and Campylobacter growth supplement. Strains utilized in this study were common pathogens (Staphylococcus aureus, Streptococcus pyogenes, et al.), anaerobes, fastidious pathogens (Bacteroides fragilis, Campylobacter jejuni, Prevotella melaninogenica), uncommon pathogens (Actinobacter baumannii, Enterococcus faecalis, Streptococcus agalactiae). Positive culture rates were evaluated in each medium and measured via spectrophotometry at 660 nm. RESULTS: In vitro, all strains used in this study grew more quickly and densely in MBC media. CONCLUSION: Our results suggest that MBC media in a new enriched broth may improve bacterial culture rates in cellulitis patients. It will be necessary to study the efficacy of the MBC media in the culturing etiologic agents from tissues of cellulitis patients.

Cytolethal Distending Toxin Production, Genotypes and Atimicrobial Susceptibility of Campylobacter jejuni Isolates from Diarrhea Patients and Chickens

Campylobacter jejuni isolates from diarrhea patients and chickens in 2008 in Iksan, Korea were tested for biochemical characteristics, and for possession of genes hipO, mutated gyrA, and cdtB. Among the chickens tested 52% carried C. jejuni. All 28 patient isolates and 48 chickens isolates had typical biochemical characteristics, except for nalidixic acid resistance. All isolates from patients and chickens were resistant to ciprofloxacin, and had mutated gyrA gene indicating good correlation of the two tests. Analysis of pulsed-field gel electrophoresis (PFGE) pattern of SmaI-restricted DNA of 53 isolates showed 14 clusters. Twenty-eight patient isolates and two chicken isolates (57%) showed an identical pattern (cluster 9). Chicken isolates C37 and C48 (cluster 2), C31 and C33 (cluster 3), C29, C34, C35, and C36 (cluster 4), and C43, C44 (cluster 6) had identical patterns. All patient isolates, compared to 87% and 80% of chicken isolates, were susceptible to amikacin and chloramphenicol, respectively. Antibiotics with the lowest MIC90 were imipenem, gentamicin, and erythromycin, whereas, those with the highest were ampicillin and tetracycline. In conclusion, C. jejuni carriage rate of chickens in Iksan, Korea, was high, all 28 isolates from patients and two from chickens were an identical clone, whereas isolates from patients and remaining chickens were different clones with only 62% similarity, all isolates had hipO and cdtB genes, and all isolates were resistant to ciprofloxacin.

Two Cases of Vibrio fluvialis Bacteremia in Patients Undergoing Cancer Chemotherapy / 대한임상미생물학회지

Vibrio fluvialis is a haplophilic gram-negative bacterium normally found in coastal water and seafood and causes gastroenteritis. There have been a few reports on V. fluvialis gastroenteritis in Korea, but no previous report of isolation from blood. We isolated V. fluvialis from the blood of two patients undergoing cancer chemotherapy.

Comparison of Biological and Genetic Characteristics Between Sucrose-Fermenting and Sucrose-Nonfermenting Vibrio vulnificus Isolates

Twelve strains of V. vulnificus isolated from clinical specimens in 2002~2004 in Jeollado province were determined for their biologic groups, serotypes, presence of vvhA (hemolysin/cytolysin) gene, DNA sequence, and PFGE patterns of NotI-restricted genomic DNA. The following results were obtained. All 12 isolates were biogroup 1, and API 20E profiles were: 5146105 for 5 (41.7%) isolates, and 5148125 for 2 isolates with sucrose fermentation. Ten (83.3%) of the 12 isolates was V. vulnificus serotype O4A, and two sucrose-fermenting isolates belonged to serotype O2. Alleles of cytolysin-hemolysin gene were detected in all 12 isolates. The nucleotide sequences of vvhA genes from strains WKHC 212 and WKHC 221 showed 94~97% similarity compared with those from previously reported 7 strains, YJ016, CMCP6, L-180, CDC B3547, IF Vv10, CIP 75.4T and CNRVC 970121. PFGE of NotI-restricted genomic DNA from the 12 isolates showed approximately 48.5 to 873-kb fragments and they were clustered to five (A to E) patterns. Two sucrose-fermenting isolates belonged to pattern D with 95% similarity with each other. Two strains isolated from two different patients had two identical patterns C and D. It is concluded that sucrose-fermenting strains also exist among clinical isolates of V. vulnificus in Korea, and they can be identified by using API 20E system, and by detecting vvhA gene. DNA sequences and PFGE pattern of NotI-restricted genomic DNA suggested that the two sucrose-fermenting isolates belonged to an identical clone, and two strains each isolated from two different patients belonged to two identical clones.

Annual Report on External Quality Assessment of Clinical Microbiology Laboratory in Korea (2003) / 임상검사와정도관리

Three trials of external quality assessment for clinical microbiology laboratory and two workshops were performed in 2003. A total of 19 specimens were distributed. Six specimens were distributed to 241 laboratories with 231 returns in Trial I, Five specimens to 241 laboratories with 225 returns in Trial II, and seven specimens to 245 laboratories with 220 returns in Trial III. The percentages of fully correct results of E. coli, E. faecalis, S. aureus, P. aeruginosa, K. pneumoniae, Candida albicans, P. aeruginosa, S. aureus, E. faecalis, K. pneumoniae, E. coli, and Candida tropicalis were 99%, 83%, 99%, 89%, 97%, 92%, 90%, 98%, 83%, 90%, 99%, and 63%, respectively. The standard deviation (SD) of inhibition zone diameter against each antibiotic was calculated. The within-one-SD percentages on disk diffusion test against ciprofloxacin, imipenem, ampicillin, cefotaxime, and cephalothin of E. coli (M0301) were 86%, 78%, 86%, 91%, and 76%, respectively. Those against vancomycin and teicoplanin of E. faecalis (M0302) were 77% and 95%, respectively. Those against vancomycin, oxacillin, penicillin G, clindamycin, erythromycin, ciprofloxacin, gentamicin and teicoplanin of S. aureus (M0303) were 82%, 80%, 81%, 81%, 79%, 80%, 88%, and 90%, respectively. Those against ciprofloxacin, gentamicin, imipenem, ceftazidime, and piperacillin of P. aeruginosa (M0304) were 73%, 88%, 85%, 83%, and 78%, respectively. Those against ciprofloxacin, imipenem, ampicillin, cefotaxime, and cephalothin of K. pneumoniae (M0305) were 89%, 89%, 87%, 81% and 86%, respectively. Thirty-five laboratories on Trial I and Trial II had reported the both results of disk diffusion and MIC methods. Seven laboratories use disk diffusion method or MIC method according to the bacterial species. The performance on the automated or E-test susceptibility tests was generally good. In conclusion, it is necessary that the quality assurance of the individual laboratories should be improved in the identification of Candida tropicalis and Enterococcus spp., and in susceptibility tests against oxacillin, erythromycin and ciprofloxacin of S. aureus, and cephalothin and imipenem of E. coli and vancomycin of E. faecalis in case of disk diffusion method.

Inhibitory effects of Caesalpinia sappan on growth and invasion of methicillin-resistant Staphylococcus aureus

No abstract available.

Evaluation of a Modified Scheme for the Species Identification of Enterococci / 대한임상미생물학회지

BACKGROUND: Rapid species identification of enterococci is necessary for optimal treatment of infected patients as they are frequently resistant to various antimicrobial agents. Minimal identification scheme is necessary to cut the laboratory cost. In this study, a minimal identification system was modified to expand the identifiable species. METHODS: Performance of MGP test was compared to that of MIO motility test. Colonies on blood agar were used to inoculate primary identification media: SFA, BEAA, mannitol agar, tellurite agar, sorbose agar and MGP agar, which were prepared in biplates. Pigment production was tested when necessary using colonies on a blood agar. Isolates, which were not identifiable by the primary test, were inoculated to secondary test media: ADH, and arabinose-, raffinose- and sucrose-containing CTA. Vitek GPI cards were used to test isolates with a doubtful identification or no identification. RESULTS: MGP test was selected for the modified scheme, as it was more rapid and accurate than motility test. Among the 879 clinical isolates of enterococci, 462 (52.6%) and 3 (0.3%) were identified as E. faecalis and E. casseliflavus, respectively, by the primary test only. With the additional secondary tests, 379 (43.1%) isolates were identified as E. faecium. Vitek test showed the identification of 4 isolates with atypical test results and 5 isolates of rare species by modified scheme were correct. Nine isolates (1.0 %) were not identifiable by the modified scheme. CONCLUSIONS: The modified minimal identification scheme which included MGP test identified most E. faecalis isolates rapidly and accurately. Most of E. faecium isolates were identified with the additional secondary tests. In conclusion, the system is useful for the identification of commonly isolated species of enterococci.

Efficacy of Bactericidal Activity of Disinfectants and Antibiotics against MRSA

MRSA strains cause serious nosocomial infections. The rate of MRSA among Staphylococcus aureus isolated in Korea is about 70 - 80%. The treatment for MRSA infection is vancomycin. But vancomycin has several side effects and its therapeutic rate is 60 - 75%. Therefore the disinfectants play an important role in preventing and treating MRSA infection. In this study, 44 MRSA isolates were obtained from Wonkwang University Hospital, and examined for the efficacy of disinfectants commonly used in hospital. The tested disinfectants were chlorohexidine (Hibitan(R)), H2O2, tego, Gentian Violet, potadine, chlorohexidine gluconate (Microshield(R)), boric acid, alcohol, zepanon, acetic acid, and combinations of these disinfectants. MRSA studied were killed after exposure to chlorohexidine gluconate (Microshield (R)), alcohol, zepanon, alcohol+potadine, and alcohol+Gentian Violet within 30 seconds. But, tego, boric acid, and Gentian Violet+acetic acid could not kill MRSA after 30 minutes. Agar dilution minimal inhibitory concentration test was done with cephalothin, ciprofloxacin, clindamycin, erythromycin, fusidic acid, gentamicin, mupirocin, oxacillin, penicillin G, rifampin, tetracycline, and vancomycin. We found that bactericidal activity of vancomycin, fusidic acid, and mupirocin were good. In conclusion, this study provided useful information: 75% alcohol is the best disinfectant for wound dressing, 4% chlorohexidine gluconate(Microshield(R)) is useful for hand washing, and zepanon is useful for ward cleansing. Vancomycin-resistant Staphylococcus aureus was not found in our study.

A Case of Vibrio cholerae non-O1/O139 Peritonitis / 대한임상미생물학회지

Vibrio cholerae strain other than O1 and O139 (Vibrio cholerae non-O1/O139) are associated with sporadic diarrhea and have often been reported in association with extraintestinal infections. We report a case of peritonitis by V. cholerae non-O1/O139 in 43-year-old male who was diagnosed cirrhosis. He, was complained of abdominal distension and fever without history of consumption of raw sea food and exposure to sea water. Gram negative bacilli were cultured from his peritoneal fluid and identified as V. cholerae sero group O14.

A Case of Vibrio cholerae non-O1/O139 Peritonitis / 대한임상미생물학회지

Vibrio cholerae strain other than O1 and O139 (Vibrio cholerae non-O1/O139) are associated with sporadic diarrhea and have often been reported in association with extraintestinal infections. We report a case of peritonitis by V. cholerae non-O1/O139 in 43-year-old male who was diagnosed cirrhosis. He, was complained of abdominal distension and fever without history of consumption of raw sea food and exposure to sea water. Gram negative bacilli were cultured from his peritoneal fluid and identified as V. cholerae sero group O14.

Roles of Nitric Oxide and Tumor Necrosis Factor in Liver Inloammation Induced by C . parvum and LPS / 대한면역학회지

No abstract available.

Biological characteristics and serovars of vibrio vulnificus

No abstract available.