Genotypic subtyping of the HIV-1 polymerase gene in 30 naåve patients from Thailand.

To investigate the subtype classification of the circulating virus strains among infected Thai patients with human immunodeficiency virus type 1 (HIV-1). A random population of patients who were HIV-1 antibody positive after two independent screening assays was selected. HIV RNA from plasma samples was reverse-transcribed and amplified with specific primers that annealed to conserve regions of the HIV-1 pol gene. Amplified products were sequenced directly by using an automated sequencer. The sequencing products represent about 1.2 kb of the pol gene from each patient and they were phylogenetically analyzed and compared to the corresponding pol sequences of the published HIV-1 sequences of known genotypes. Genotype E was found in 25 of 30 patients (83.3%), and 5 patients (16.7%) were HIV-1 genotype B. The result confirmed that HIV-1 subtype E is still predominant in Thailand. Genotype B is found frequently, but there have been no examples of genotype A. In concordance with the serotypic assay, which was previously reported using the V3-peptide enzyme immunoassay (V3-PEIA), the genotypic assay of subtype E was high, at 80% and 83.3% in serotyping and genotyping, respectively. These findings of two subtypes with low heterogeneity indicate that Thailand may be a desirable site for evaluating candidate HIV-1 antiretroviral drugs and vaccines. The mixture of subtype E and B' strains also offers the opportunity to study phenotypic differences between the two subtypes.

Risk factors for neonatal Klebsiella septicemia in Srinagarind Hospital.

Three years' data were analysed to assess the risk factors for neonatal Klebsiella septicemia in Srinagarind Hospital. The incidence of Klebsiella septicemia was 4.1 per 1,000 livebirths or 5.2 per 100 discharged infants. Eighty-two per cent of infected cases were low birth weight infants and 67.7% were born prematurely. From multivariate analysis, the risk factors were endotracheal intubation (OR 31.57, 95% CI 289-343.82) and central venous catheterization (OR 16.99, 95% CI1.15-250.37). The overall mortality rate was 67.7%. Periodic review and continuous reinforcement of infection control policies in the neonatal unit are of paramount importance to decrease the incidence of nosocomial infection and successful control of outbreaks as well.

Characterization of Pseudomonas pseudomallei antigens by SDS-polyacrylamide gel electrophoresis and western blot.

Immunological characterization of various Pseudomonas pseudomallei preparations was carried out by SDS-PAGE and Western blot using sera from infected humans and from patients with other bacterial infections. Somatic (SOM) and partially purified cell extracts (PCE) gave more complex SDS-PAGE patterns: M(r) ranged from 86 to 12.7 and 48 to 10 kDa, respectively. The culture-filtrated antigens (CF) from 3 different kinds of synthetic media consisted of fairly simple profiles with common bands M(r) of 40, 26 and 16 kDa. PCE and CF reacted specifically with infected human sera; SOM did not. The components with M(r) of 40 kDa in CF reacted consistently with all infected sera but failed to react with sera infected with Escherichia coli, Enterobacter spp., Klebsiella pneumoniae, Proteus mirabilis, Salmonella spp., Staphylococcus aureus, Streptococcus spp., Pseudomonas aeruginosa and P. stutzeri. This peptide was demonstrated to be a major component in CF thus suggesting its potential for development of immunodiagnostic methods for melioidosis.

Rhinocerebral mucormycosis: a report of eleven cases.

Rhinocerebral mucormycosis (RCM) is a rare, fulminant fungal infection that usually occurs in diabetic or immunocompromised patients. The mortality rate has been reduced recently with the advent of amphotericin B combined with aggressive surgery. Eleven RCM patients have been treated over the past five years at Srinagarind Hospital. Eight had underlying diabetes, five had renal failure and three of them had both. In eight patients, the diagnosis was established by KOH preparation before histological confirmation. Only two cases revealed positive cultures for Rhizopus spp and Cunninghamella spp. All patients underwent surgical treatments (extensive debridement, 8 cases; sphenoidectomy, 7 cases; ethmoidectomy 8 cases; maxillectomy 5 cases and orbital exenteration, 6 cases). Amphotericin B was administered to all patients as soon as the diagnosis of RCM was made. Only three patients survived. Early diagnosis and cooperation among ophthalmologist, otolaryngologist and physician are the most important factors for the survival of patients with mucormycosis.

Discriminant analysis among septicemic melioidosis and other bacterial septicemia.

The clinical manifestations of septicemic melioidosis and other bacterial septicemia were studied at Srinagarind Hospital, Khon Kaen University. Forty-three cases of septicemic melioidosis and 68 non-melioidosis septicemia cases were analysed. By univariate analysis, the following clinical features are associated with septicemic melioidosis: male patients; age below 45 years; underlying diabetes mellitus or renal failure; pulmonary infection, impending respiratory failure and multiorgan involvement, while abdominal pain and urinary tract infection were more common in non-melioidosis septicemia. By using discriminant analysis and logistic regression, 3 features (diabetes mellitus, multiorgan involvement, and no abdominal pain or pulmonary infection) could discriminate the two groups with the accuracy of more than 85 per cent.