BACKGROUND: Increased resistance rates to macrolide-lincosamide-streptogramin B (MLSB) antibiotics among clinical isolates of staphylococci are considered as a consequence of an expanded use of these antibiotics in the treatment of Gram-positive infections. The proportion of MLSB resistance phenotypes of staphylococci is quite different by geographical variations and study periods. The aim of the present study was to determine the distribution of MLSB resistance phenotypes among clinical isolates of staphylococci in a university hospital. METHODS: The MLSB resistance phenotypes of clinical isolates of staphylococci were investigated by the double-disk diffusion test using erythromycin and clindamycin disks. RESULTS: Of 7,916 isolates, 55.7% exhibited a constitutive resistance phenotype (cMLSB) whereas 8.1% expressed an inducible resistance phenotype (iMLSB). Among 3,419 coagulase-negative staphylococci (CNS), 32.6% and 10.0% exhibited cMLSB and iMLSB resistance phenotypes, respectively. Of 4,497 Staphylococcus aureus isolates, 73.1% and 6.8% were cMLSB and iMLSB resistance phenotypes, respectively. cMLSB was detected among 90.2% of methicillin-resistant S. aureus (MRSA), 46.5% of methicillin-resistant CNS (MRCNS), 3.2% of methicillin-susceptible CNS (MSCNS), and 2.2% of methicillin-susceptible S. aureus (MSSA). iMLSB was detected among 16.5% of MSSA, 11.5% of MRCNS, 6.7% of MSCNS, and 4.4% of MRSA. CONCLUSION: MLSB resistance was more prevalent among S. aureus isolates than CNS strains. Although cMLSB was the most frequently detected resistance phenotype among the total staphylococcal isolates, methicillin-susceptible strains exhibited somewhat higher iMLSB resistance rates compared with methicillin-resistant strains.
Anti-Bacterial Agents ; Clindamycin ; Diffusion ; Erythromycin ; Methicillin Resistance ; Phenotype ; Staphylococcus aureus

BACKGROUND: Staphylococcus saprophyticus is the second most common cause of urinary tract infections (UTIs) in young women. As little is known about the incidence of UTIs caused by this organism in Korea, we examined its frequency and clinical characteristics. METHODS: We analyzed the frequency of S. saprophyticus among organisms isolated from urine specimens in Wonju Christian Hospital from July 1996 to June 2008 and reviewed clinical characteristics retrospectively. RESULTS: Of 24,277 strains isolated from urine specimens during the past 12 years, 21 (0.09%) were S. saprophyticus. Outpatients were more common in the S. saprophyticus group than in all patients group (12 of 21, 57% vs 5,098 of 24,277, 21%). The incidence of S. saprophyticus in women was the highest in the group of 15 to 34 years of age. Monthly distributions of isolates were almost constant in all patient groups, while 16 of 21 (76%) cases of the S. saprophyticus group occurred in summer and fall (June to November). CONCLUSION: The fequencies of S. saprophyticus among organisms isolated from urine specimens in all patient groups and women were 0.09% and 0.17%, respectively, and are much lower than those in other countries. However, we need further studies to examine the prevalence of S. saprophyticus UTIs in other regions of this country.
Female ; Humans ; Incidence ; Korea ; Outpatients ; Prevalence ; Staphylococcus ; Staphylococcus saprophyticus ; Urinary Tract ; Urinary Tract Infections

Rothia dentocariosa, a pleomorphic gram-positive branching bacillus, is a common inhabitant of the nose and throat. It is a well-known causative agent of dental plaques and periodontal diseases. Although generally regarded as having a low virulence to humans, R. dentocariosa has been recognized as causative agents of infective endocarditis and bacteremia with increasing frequency. Consequently, it can be a very serious pathogen when isolated from usually sterile sites such as blood or cerebrospinal fluid. We report a case of Rothia dentocariosa bacteremia without endocarditis in a 17-month-old male patient with fever, vomiting and diarrhea.
Bacillus ; Bacteremia ; Endocarditis ; Fever ; Humans ; Infant ; Male ; Nose ; Periodontal Diseases ; Pharynx ; Vomiting

Parvimonas micra is a non-spore-forming anaerobic gram-positive coccus, widely distributed as normal flora in the skin, vagina and mucosa, and able to cause opportunistic infections, particularly endocarditis and brain abscess following dental manipulations. A 49-year-old woman was hospitalized due to fever and headache. She had been diagnosed with periodontitis at the beginning of fever. A brain abscess was noted in the right temporal lobe on the brain CT, and she was treated with ceftriaxone, isepamicin and metronidazole. In the next day, abscess was aspirated and drained by a surgical procedure. An organism was isolated from an anaerobic culture of the abscess aspirate, and was identified as P. micra by a commercial kit and 16S rRNA sequencing.
Abscess ; Brain ; Brain Abscess ; Ceftriaxone ; Endocarditis ; Female ; Fever ; Gentamicins ; Headache ; Humans ; Metronidazole ; Middle Aged ; Mucous Membrane ; Opportunistic Infections ; Peptostreptococcus ; Periodontitis ; Skin ; Temporal Lobe ; Vagina