Emergence of rifampin-resistant Rhodococcus equi with several types of mutations in the rpoB gene among AIDS patients in northern Thailand

The antimicrobial susceptibilities of 30 Rhodococcus equi isolates obtained from 30 patients between 1993 and 2001 in northern Thailand were investigated. The MICs showed a tendency toward resistance to various antibiotics but sensitivity to imipenem, minocycline, vancomycin, and teicoplanin (MICs, /=64 micro g/ml) to rifampin. PCR amplification and DNA sequencing of the rpoB gene and molecular typing by pulsed-field gel electrophoresis (PFGE) were performed for eight R. equi isolates from eight AIDS patients with pneumonia or lung abscess caused by R. equi between 1998 and 2001, including one low- and three high-level rifampin-resistant isolates. As a result, two high-level rifampin-resistant strains with PFGE pattern A had a Ser531Trp (Escherichia coli numbering) mutation, and one high-level rifampin-resistant strain with PFGE pattern B had a His526Tyr mutation, whereas one low-level rifampin-resistant strain with PFGE pattern C had a Ser509Pro mutation. Four rifampin-susceptible strains with PFGE patterns D and E showed an absence of mutation in the rpoB region. Our results indicate the presence of several types of rifampin-resistant R. equi strains among AIDS patients in northern Thailand.     

Postmortem diagnosis of sudden unexpected death from Streptococcus suis type 2 infection: A case report

Streptococcus suis causes meningitis, septicemia, arthritis, endocarditis and death in both pigs and humans. Sudden death is rarely documented in the forensic field and almost all cases were diagnosed pre-mortem. Here we report a 49-year-old man who died from S. suis type 2 infection. S. suis was identified as the causative pathogen using bacterial culture, standard biochemical and coagglutination tests, specific DNA amplification by polymerase chain reaction, and histopathologic examination. We discuss the postmortem investigation of a suspected S. suis infection.     

Identification of virulence-associated antigens and plasmids in Rhodococcus equi from patients with acquired immune deficiency syndrome and prevalence of virulent R. equi in soil collected from domestic animal farms in Chiang Mai,Thailand

The prevalence of virulent Rhodococcus equi in soil collected from 17 domestic animal farms (from 12 cattle, 1 pig, and 4 horse farms) and in 6 clinical specimens from patients with acquired immune deficiency syndrome (AIDS) in Chiang Mai, Thailand, was investigated. The isolates were tested for the presence of 15-17-kDa antigens (VapA) and a 20-kDa antigen (VapB) by immunoblotting and for the presence of virulence plasmid DNA. Rhodococcus equi was isolated from most soil samples (68 of 80) obtained from the 17 farms, with 2.0 x 10(2) to 6.0 x 10(5) colony-forming units per gram of soil. We detected VapA in none of the 537 isolates from the soil samples. In one isolate from a pig farm, both VapB and virulence plasmid DNA were detected. Of the 6 clinical isolates from patients with AIDS, however, 4 isolates contained both VapB and virulence plasmid DNA. The remaining 2 isolates were avirulent.     

Roseomonas gilardii subsp rosea, a pink bacterium associated with bacteremia: the first case in Thailand

Roseomonas is a pink-pigmented, non-fermentative, gram-negative coccobacillus bacterium. Human infections caused by Roseomonas are very rare. We report the first case of bacteremia associated with Roseomonas gilardii subsp rosea in Thailand. The bacterium was isolated from blood culture and identified by cellular morphology, characteristics of colonies on blood agar, extensive biochemical tests and 16S ribosomal DNA sequencing.     

Incidence and presence of virulence factors of Streptococcus suis infection in slaughtered pigs from Chiang Mai, Thailand

This study was designed to determine the incidence of Streptococcus suis infection in slaughtered pigs raised in industrial facility and backyard system in Chiang Mai City, Thailand. A total of 90 tonsils and submaxillary salivary gland/lymph node samples from slaughtered pigs raised in industrial facility and 122 samples from slaughtered pigs raised in backyard system were collected. Isolation and identification of S. suis were conducted using standard bacteriological methods. Farm management and risk factor data were collected by a questionnaire. Serotyping and presence of virulence factor genes, epf, mrp and sly, were determined by multiplex PCR assay. The overall incidence of S. suis in this study was 9% (n = 212) and the incidence is significantly higher in districts located at a greater distance south of Chiang Mai City. S. suis serotype 2 was present more in healthy pigs (43%) than ill pigs (10%). Every S. suis isolate carried mrp and sly and ill pigs carried epf (80%) more than healthy pigs (57%). However, the probability of S. suis serotype 2 with epf+ (0.245) detected in healthy pigs was higher than in ill pigs (0.08) indicating people may have a higher risk of being infected with S. suis from healthy than ill pigs.     

Pulmonary infection caused by Rhodococcus equi in HIV-infected patients: report of four patients from northern Thailand

We report four human immunodeficiency virus (HIV)-infected patients (3 men and one woman, average age, 34.3 years) with pulmonary infection (two with pneumonia and two with lung abscess) caused by Rhodococcus equi. These patients, who presented with fever and productive cough, were admitted to Nakornping Hospital in northern Thailand. Chest roentgenograms showed pulmonary infiltration and/or cavitary lesions. Their conditions were poor because of severe anemia, and transfusion was necessary in three of the four patients. Before culture results were available, the etiologic microorganisms identified in sputum smears were gram-positive and acid-fast coccobacilli. One of the four patients had a mixed infection with R. equi and Salmonella enteritidis. The mean CD4 lymphocyte count in the three tested patients was 10/mm³ (CD4/CD8 ratio = 0.057). Four isolates of R. equi were sensitive to imipenem, minocycline, erythromycin, vancomycin, and ciprofloxacin (minimum inhibitory concentrations; MICs, ≤1.56 μg/ml), but resistant to most β-lactam antibiotics. Two isolates were sensitive (MICs, 0.20 and 0.78 μg/ml) and two resistant (MICs 50 and >100 μg/ml) to rifampicin. Two patients were treated with erythromycin plus rifampicin, while the other two were treated with anti-tuberculous drugs. However, treatment was ineffective; three patients subsequently died because of respiratory failure, and one patient did not improve and was transferred to another hospital in her hometown. Received: June 23, 2000 / Accepted: August 13, 2000     

Impact of incomplete plan to treatment results of concurrent weekly cisplatin and radiotherapy in locally advanced cervical cancer

To evaluate the efficacy of incomplete treatment protocols of cisplatin in concurrent chemoradiation for locally advanced cervical carcinoma. This retrospective study was performed in 165 consecutively treated patients with locally advanced cervical cancer who received a weekly cisplatin regimen. The number of weekly cisplatin cycles of each patient was recorded and used to discriminate between patients. Local control, disease free survival, distant metastasis-free survival, and toxicities were calculated using the software package SPSS version 15.0. Ninety-two patients (55%) completed the planned protocol of six cycles of weekly cisplatin. With the median follow-up time of 38.2 months, the 3-year local control rate differed significantly in the two patient groups (95.4% of 6 cycles versus 84.8% of < 6 cycles; p = 0.028). No statistical significance was observed for disease-free survival (74.6% versus 74.5%; p = 0.22) and distant metastasis-free survival (76.5% vs. 75.7%; p = 0.88). In conclusion, the plan completion of concurrent cisplatin with radiotherapy was responsible for better local control. However, differences in disease-free survival and distant metastasis-free survival were not statistical significant.     

A phase II study of oxaliplatin with 5-FU/folinic acid and concomitant radiotherapy as a preoperative treatment in patients with locally advanced rectal cancer

Objective:

To evaluate the activity and safety of adding oxaliplatin to a standard chemoradiotherapy schema, including 5-fluorouracil (5-FU)/folinic acid (FA), in locally-advanced rectal cancer (LARC).

Methods:

Two cycles of oxaliplatin 130 mg/m² plus FA 20 mg/m² bolus for 5 days and 5-FU 350 mg/m² continuous infusion for 5 days were given during week 1 and 4 of pelvic radiotherapy 46 Gy. Patients with a T3/4 and/or node-positive rectal tumour were eligible. Surgery was performed 4–6 weeks after radiotherapy. The primary endpoint was to determine the rate of pathological response. Secondary endpoints were to assess the rate of clinical response and the safety profile.

Results:

Between March 2005 and January 2009, a total of 35 patients were enrolled. The pathological down-staging rate was 79% with a pathological complete response rate of 17%. The overall clinical response rate (assessed by computed tomography or transrectal ultrasound) was 77%. Grade 3 diarrhoea and Grade 3 neutropaenia were reported in 14% and 11% of the patients, respectively. Eleven patients did not undergo surgery: four of them refused the operation, and seven patients were inoperable due to disease progression. In 24 patients who had surgery, a sphincter-preserving procedure could be performed in 29%. At the median follow-up time of 28.1 months, 25 patients (71%) survived with no evidence of disease.

Conclusion:

The promising results in terms of pathological response, and the associated good safety profile of a regimen of oxaliplatin plus 5-FU/FA with concomitant radiotherapy, suggest that the regimen could be used in LARC.