Serotypes and antimicrobial susceptibilities of Streptococcus pneumoniae isolated from hospitalized patients in Thailand.

Two hundred seven Streptococcus pneumoniae isolates were obtained from patients admitted to Siriraj Hospital. One hundred two, and 105 isolates were from sterile sites and non-sterile sites, respectively. They were serotyped by Quellung reaction with specific antisera from Statens Serum Institut; 81.6% of these pneumococci were typeable. These serotypes were included in the 23-valent pneumococcal polysaccharide vaccine. The five most common serotypes were serotype 6 (22.5%), followed by serotype 23 (18.9%), serotype 19 (16.6%), serotype 3 (7.7%) and serotype 11 (5.3%). Among typeable pneumococci (169 isolates), 52.7% were from sterile sites and 47.3% were from non-sterile sites. Serotypes 6, 23 and 19 were the predominant serotypes isolated from sterile sites. Of the 9 drugs tested, pneumococcal isolates were sensitive to ofloxacin (99%), ciprofloxacin (81.5%), meropenem (80%), imipenem (66.5%), ceftriaxone (65%), cefotaxime (63%), erythromycin (58%), penicillin (48%), and trimethoprim-sulfamethoxazole (34.5%).

Brain abscess due to Listeria monocytogenes: first case report in Thailand.

Brain abscess with bacteremia caused by Listeria monocytogenes in a young woman with immune thrombocytopenic purpura was reported. The clinical features included fever, headache, and left-side weakness. Computed tomography and magnetic resonance imaging of the brain showed a large single abscess at the right frontoparietal area. L. monocytogenes was isolated from a blood culture. The patient promptly received a surgical drainage. Because she had a history of penicillin allergy, and the organism was resistant to ampicillin, she was treated with trimethoprim-sulfamethoxazole (TMP-SMX) alone for 12 months. During a one-year follow-up period, the patient improved and her neurological deficit gradually recovered. This is the first case of listerial brain abscess in Thailand that was successfully treated with TMP-SMX monotherapy and surgical drainage.

The first pediatric case of Staphylococcus aureus with heterogenous resistant to vancomycin endocarditis in Thailand.

Staphylococcus aureus with reduced susceptibility to vancomycin has been reports worldwide. Here we report the first pediatric case of heterogeneous vancomycin intermediate resistance Staphylacoccus aureus (hVISA) causing endocarditis in Thailand. A 4 months old girl with truncus arteriosus type IV and ventricular septal defect developed methicillin-resistant S. aureus (MRSA) bacteremia and endocarditis after total repair operation. The patient did not respond to combination antimicrobial treatment including vancomycin. The strain was susceptible to trimethoprim-sulfamethoxazole and vancomycin by conventional antimicrobial susceptibily test. The vancomycin minimal inhibitory concentration by E-test was 2 microg/ml. The strain was judged to be possible heteroresistant when screening was done by one-point population analysis. The subsequent population analysis and testing for the emergence of mutants with reduced susceptible to vancomycin confirmed that this strain was hVISA. Despite the treatment with vancomycin, amikacin, rifampicin and cotrimoxazole, the patient died. hVISA should be suspected in MRSA infections that were refractory to vancomycin therapy could be due to. The emergence hVISA underscored the importance of the prudent use of antibiotics, the laboratory capacity to identify MRSA and hVISA and proper communication with treating clinicians, and the meticulous infection-control measures to prevent transmission.

Bacterial study of autopsy specimens.

Autopsy reports were reviewed for the detection of infectious diseases at autopsy and to determine what extent an infectious process was involved in the patient's death. The present study was performed to analyze bacterial data of autopsy specimens in Siriraj Hospital during 1992-1999. Various autopsy specimens were cultured including heart blood, bronchus, lung, brain, cerebro-spinal fluid, pleural fluid, ascitic fluid, peritoneal fluid, liver, kidney, pericardial fluid, spleen and gall bladder From 781 autopsy specimens 502 (64.28%) were positive for bacterial pathogens. The five most common bacterial pathogens isolated from the present study were nonfermentative gram-negative rods followed by Klebsiella pneumoniae, Salmonella serogroup E, Escerichia coli and Acinetobacter anitratus, respectively. The ante mortem diagnosis by clinicians was correct 56% regarding to retrospectively analysis of septicemia/septic shock versus autopsy culture from heart blood

Pneumococci: drug susceptibilities and preliminary epidemiological studies by penicillin binding protein genotyping.

A collection of 307 pneumococcal isolates form 84 children and 223 adults admitted to Siriraj Hospital were separated into two groups, penicillin-susceptible (PSSP) and penicillin-nonsusceptible (PNSP). Each group was tested for susceptibilities to 12 drugs (cefuroxime, amoxicillin, chloramphenicol, tetracycline, cefotaxime, ceftriaxone, imipenem, meropenem, ciprofloxacin, ofloxacin, erythromycin and co-trimoxazole). PSSP were susceptible to cefuroxime (87.5%), amoxicillin (100%), chloramphenicol (84.7%), tetracycline (45.8%), cefotaxime (99%), ceftriaxone (99%), imipenem (99%), meropenem (100%), ciprofloxacin (76%), ofloxacin (99%), erythromycin (94.8%) and co-trimoxazole (61.5%). PNSP were resistant to most drugs, except for amoxicillin (99%), ofloxacin (99%) and ciprofloxacin (86.3%). Twenty-two pneumococcal isolates belonging to the three most common serotypes (6, 19, 23) were randomly selected for studies of the pbp2b gene with RFLP. There were 7 distinct pbp2b RFLP patterns. RFLP pattern 1 was the most predominant resistant pattern. The RFLP pattern 2 was found only in PSSP.