Emergence of a unique O3:K6 clone of Vibrio parahaemolyticus in Calcutta, India, and isolation of strains from the same clonal group from Southeast Asian travelers arriving in Japan.

Active surveillance of Vibrio parahaemolyticus infection among hospitalized patients in Calcutta, India, was initiated in January 1994. The incidence of cases of V. parahaemolyticus infection suddenly increased in February 1996 and has remained high since then. One hundred thirty-four strains of V. parahaemolyticus isolated from January 1994 to August 1996 were examined for serovar, the presence of the thermostable direct hemolysin gene (tdh) and tdh-related hemolysin genes (trh1 and trh2), production of urease, and antibiogram. Strains of the O3:K6 serovar appeared for the first time in February 1996. The O3:K6 serovar strains accounted for 50 to 80% of the strains isolated during the high-incidence period (February to August 1996). All of the serovar O3:K6 strains carried the tdh gene but not the trh genes and did not produce urease. All of the isolates except two were sensitive to all of the antibiotics tested. These and the results of analysis by an arbitrarily primed PCR method indicated that the O3:K6 serovar strains belong to a unique clone. When the O3:K6 serovar strains, isolated from travelers arriving in Japan from Southeast Asian countries, were compared by the arbitrarily primed PCR method, the strains isolated between 1982 and 1993 were distinct from Calcutta O3:K6 while the strains isolated in 1995 and 1996 were indistinguishable from the Calcutta O3:K6 strains. The results suggest that this unique O3:K6 clone may have become prevalent not only in Calcutta but also in Southeast Asian countries very recently. Not only the O3:K6 strains but also the non-O3:K6, tdh-bearing strains isolated in 1996 produced thermostable direct hemolysin at high levels, and thus the level of hemolysin produced does not appear to have influenced the high incidence of serovar O3:K6 strains.     

Decreased natural and antibody-dependent cellular cytotoxic activities in intravenous drug abusers

Peripheral blood lymphocytes from 14 adult male patients admitted to the hospital with complications of intravenous drug abuse (IDA) were examined for natural killer (NK) and antibody-dependent cellular cytotoxic (ADCC) activities, lectin-dependent cellular cytotoxicity, and interferon (IFN)- and interleukin 2 (IL-2)-induced NK activity. Serum was also assayed for circulating interferon levels and soluble factor(s) capable of suppressing the cytotoxic potential of allogeneic lymphocytes from healthy donors. IDA patients demonstrated significantly decreased levels of NK and ADCC activities compared to age- and sex-matched healthy controls. The lectin, phytohemagglutinin, could significantly enhance the cytotoxicity of IDA lymphocytes; however, activity was not completely restored to normal levels. IDA sera demonstrated a significant inhibitory effect on the NK and ADCC activities of normal allogeneic lymphocytes, and these sera contained negligible levels of circulating IFN. Although the NK activity of IDA lymphocytes could not be restored completely to normal levels by either IFN-alpha or IL-2, the percentage enhancement of cytotoxicity was remarkably higher in IDA patients with significantly reduced NK activity than that observed using PBL from patients with near normal NK activity. The ability of IFN or IL-2 to enhance the decreased cytotoxicity of PBL from drug abusers suggests a novel therapeutic approach to the management of the complications of IDA.     

Tardive dyskinesia and the primary psychiatric diagnosis

Over 300 patients were assessed for the presence of tardive dyskinesia in relation to the primary psychiatric diagnosis. Patients with organic mental syndrome or bipolar disorder showed a significantly (P < .01) higher prevalence of tardive dyskinesia (41% and 42%, respectively) than did those with schizophrenia (24.5%). This difference was not related to age or duration of neuroleptic treatment. Based on these findings, the physician should remain aware of the greater possibility of tardive dyskinesia in patients with organic mental syndrome or bipolar disorder and periodically review dosage and indications for neuroleptic treatment.     

Utility of gram staining for evaluation of the quality of cystic fibrosis sputum samples

The microscopic examination of Gram-stained sputum specimens is very helpful in the evaluation of patients with community-acquired pneumonia and has also been recommended for use in cystic fibrosis (CF) patients. This study was undertaken to evaluate that recommendation. One hundred one sputum samples from CF patients were cultured for gram-negative bacilli and examined by Gram staining for both sputum adequacy (using the quality [Q] score) and bacterial morphology. Subjective evaluation of adequacy was also performed and categorized. Based on Q score evaluation, 41% of the samples would have been rejected despite a subjective appearance of purulence. Only three of these rejected samples were culture negative for gram-negative CF pathogens. Correlation between culture results and quantitative Gram stain examination was also poor. These data suggest that subjective evaluation combined with comprehensive bacteriology is superior to Gram staining in identifying pathogens in CF sputum.     

Development and evaluation of a phage typing scheme for Vibrio cholerae O139

The scenario of cholera that existed previously changed in 1992 and 1993 with the emergence of toxigenic Vibrio cholerae O139 in India. The genesis of the new serogroup formed the impetus to search for O139 phages in and around the country. A total of five newly isolated phages lytic to V. cholerae O139 strains were used for the development of this phage typing scheme. These phages differed from each other and also differed from the existing O1 phages in their lytic patterns, morphologies, restriction endonuclease digestion profiles, and immunological criteria. With this scheme, 500 V. cholerae O139 strains were evaluated for their phage types, and almost all strains were found to be typeable. The strains clustered into 10 different phage types, of which type 1 (38.2%) was the dominant type, followed by type 2 (22.4%) and type 3 (18%). Additionally, a comparative study of phage types in 1993 and 1994 versus those from 1996 to 1998 for O139 strains showed a higher percentage of phage type 1 (40.5%), followed by type 3 (18.8%) during the period between 1993 and 1994, whereas phage type 2 (32. 1%) was the next major type during the period from 1996 to 1998. This scheme comprising five newly isolated phages would be another useful tool in the study of the epidemiology of cholera caused by V. cholerae O139.     

Association between regularity in dapsone (DDS) treatment and development of deformity

The existence of an association between regularity in dapsone intake and the development of deformity was investigated in 5746 leprosy patients under treatment in South India. The incidence of deformity, year by year over a 5-year period, increased significantly with increasing levels of drug collection. The excess incidence in "more regular" patients was significant at all ages and in both sexes in nonlepromatous (N) cases. The same was true in intermediate (N?L) cases except in patients under 15 years of age. The evidence in lepromatous (L) cases was not so consistent. Independent confirmation of the presence of the association was sought through a matched case-control type of analysis with 140 N, 48 N?L, and 81 L cases, matching being undertaken with respect to sex, age, type of leprosy, year of starting treatment, and observation period. This showed that the mean regularity in cases (deformed patients) before the development of deformity was significantly higher than the mean regularity in the corresponding matched controls, the differences being particularly large among the N and N?L types. These findings raise the possibility of a causal link between regular dapsone intake and the development of deformity.