Phalguni Dutta

Genomic Diversity of Group A Rotavirus Strains Infecting Humans in Eastern India

ABSTRACT Between 1998 and 2000, a total of 266 samples were found positive for group A rotaviruses by RNA electrophoresis. Samples were collected from patients admitted to two leading hospitals in Calcutta. Serotyping could be done only with 22% of the positive samples, leaving 78% untypeable. The G (VP7 genotypes) and P (VP4 genotypes) types were determined for 159 samples by reverse transcription and multiplex PCR. The predominant genotype was G1P[8] (20%), followed by G2P[4] (15%) and G4P[8] (6%). A number of uncommon genotypes, G1P[4] (4%), G2P[8] (2.5%), G2P[6] (0.6%), G4P[4] (2.5%), and G4P[6] (1.25%), were also detected during this study period. Twenty two percent of specimens showed mixed infections, 38 (24%) of the total samples remained untypeable for either VP7 or VP4, while only 4 (2.5%) of the samples were untypeable for both genes. Eleven specimens collected from Manipur were also genotyped and revealed a very high degree of genomic reassortment.

Ciprofloxacin for treatment of severe typhoid fever in children.

Eighteen children with bacteriologically confirmed severe typhoid fever were initially treated intravenously with ciprofloxacin (10 mg/kg of body weight per day). Clinical cure with eradication of multiresistant Salmonella typhi infection was observed in 17 patients (94.4%; 95% confidence interval [CI], 84 to 100%). Children regained normal consciousness within an average of 2 days (95% CI, 1.8 to 2.2 days). The temperatures of the children returned to normal within 3.3 days (95% CI, 3.1 to 3.5 days). Complications were not observed during the hospital stay or a 3-month follow-up period. Relapse and carrier state were also not encountered during the follow-up period.

Immunogenicity, reactogenicity and safety of human rotavirus vaccine (RIX4414) in Indian infants.

Aim: This study was undertaken to assess the immunogenicity, reactogenicity and safety of two doses of an oral live-attenuated human rotavirus vaccine, strain RIX4414 (Rotarix™) in an Indian setting. Patients and Methods: Healthy infants (N=363), approximately 8 weeks of age were enrolled to receive two doses of RIX4414 vaccine (n=182) or placebo (n=181) separated by one month. To assess the immune response, blood samples were taken before vaccination and one month post-dose 2 of RIX4414/placebo. Solicited symptoms were collected for 8-days post each dose and safety data was collected throughout the study. Results: The seroconversion rate observed one month post-dose 2 in the RIX4414 group 58.3% [95% CI: 48.7; 67.4] was significantly higher when compared to the placebo group 6.3%; [95% CI: 2.5; 12.5]. The reactogenicity and safety profile was similar for both groups. Conclusions: Two doses of RIX4414 (Rotarix™) were immunogenic, had a good safety profile and were well-tolerated when administered to healthy Indian infants.

Full genomic analysis of a human group A rotavirus G9P[6] strain from Eastern India provides evidence for porcine-to-human interspecies transmission

Deduced amino acid sequence and phylogenetic analyses of a group A rotavirus G9P[6] strain (designated as mcs/13-07), detected from a 3-year-old child in Eastern India, revealed a VP8* closely related to porcine P[6] strains (P[6] sublineage 1D), and the VP7 clustered with G9 lineage-III strains. To our knowledge, this is the first report of human P[6] strain clustering in sublineage Id. Thus, to further characterize the evolutionary diversity of strain mcs/13-07, all gene segments were analyzed. VP6 and NSP4 exhibited genetic relatedness to Wa-like human subgroup II strains, while VP1-3, NSP1-3 and NSP5 were closely related to porcine strains. Based on the new classification system of rotaviruses, mcs/13-07 revealed a G9–P[6]–I1–R1–C1–M1–A8–N1–T1–E1–H1 genotype with close similarity to human Wa-like and porcine Gottfried strains. Therefore, considering the porcine-like or porcine origin of multiple gene segments, it might be tempting to assume that strain mcs/13-07 represents a rare instance of whole-virus transmission from pig to human, after which the virus evolved with time. Alternatively, it is possible that strain mcs/13-07 resulted from multiple reassortment events involving human subgroup II and porcine P[6] strains. Nevertheless, detection of strain mcs/13-07 provides further evidence for complex interspecies transmission events, which are frequent in developing countries.

Molecular Characterization of Cryptosporidium spp. from Children in Kolkata, India

ABSTRACT The intracellular parasite Cryptosporidium is responsible for severe diarrhea in immunocompromised persons in developing countries. Few studies on the characterization of the parasite in India are available. In this study, molecular characterization of the parasite from diarrheic children was carried out by PCR-restriction fragment length polymorphism analysis. At least three genotypes were identified. Out of 40 positive samples, 35 were positive for C. hominis, 4 were positive for C. parvum, and 1 was positive for C. felis. This study clearly suggests that cryptosporidiosis in this region is caused largely by anthroponotic transmission.

Double-blind, randomized, controlled clinical trial of norfloxacin for cholera.

In a double-blind, randomized clinical trial with 78 adults with acute watery diarrhea and severe dehydration, 37 subjects were positive for Vibrio cholerae. In conjunction with rehydration therapy, 13 patients received norfloxacin, 12 received trimethoprim-sulfamethoxazole (TMP-SMX), and 12 received a placebo. Norfloxacin was superior to TMP-SMX and to the placebo in reducing stool output, duration of diarrhea, fluid requirements, and vibrio excretion. TMP-SMX was no better than the placebo.

Antimicrobial Resistance, Virulence Profiles and Molecular Subtypes of Salmonella enterica Serovars Typhi and Paratyphi A Blood Isolates from Kolkata, India during 2009-2013

Enteric fever, caused by Salmonella enterica, remains an unresolved public health problem in India and antimicrobial therapy is the main mode of treatment. The objective of this study was to characterize the Salmonella enterica isolates from Kolkata with respect to their antimicrobial resistance (AMR), virulence profiles and molecular subtypes. Salmonella enterica blood isolates were collected from clinically suspected enteric fever patients attending various hospitals in Kolkata, India from January 2009 to June 2013 and were tested for AMR profiles by standard protocols; for resistance gene transfer by conjugation; for resistance and virulence genes profiles by PCR; and for molecular subtypes by Pulsed Field Gel Electrophoresis (PFGE). A total of 77 Salmonella enterica serovar Typhi (S. Typhi) and 25 Salmonella enterica serovar Paratyphi A (S. Paratyphi A) from Kolkata were included in this study. Although multidrug resistance (resistance to chloramphenicol, ampicillin, co-trimoxazole) was decreasing in S. Typhi (18.2%) and absent in S. Paratyphi A, increased resistance to fluoroquinolone, the current drug of choice, caused growing concern for typhoid treatment. A single, non-conjugative non-IncHI1 plasmid of 180 kb was found in 71.4% multidrug resistant (MDR) S. Typhi; the remaining 28.6% isolates were without plasmid. Various AMR markers (bla TEM-1, catA, sul1, sul2, dfrA15, strA-strB) and class 1 integron with dfrA7 gene were detected in MDR S. Typhi by PCR and sequencing. Most of the study isolates were likely to be virulent due to the presence of virulence markers. Major diversity was not noticed among S. Typhi and S. Paratyphi A from Kolkata by PFGE. The observed association between AMR profiles and S. Typhi pulsotypes might be useful in controlling the spread of the organism by appropriate intervention. The study reiterated the importance of continuous monitoring of AMR and molecular subtypes of Salmonella isolates from endemic regions for better understanding of the disease epidemiology.

Randomised controlled clinical trial of Lactobacillus sporogenes (Bacillus coagulans), used as probiotic in clinical practice, on acute watery diarrhoea in children

Objective  To assess the clinical efficacy of Lactobacillus sporogenes (Bacillus coagulans), as probiotic preparation, against dehydrating diarrhoea in children.

Increase in prevalence of human group A rotavirus G9 strains as an important VP7 genotype among children in eastern India

BACKGROUND In addition to four globally important group A rotavirus (GARV) VP7 genotypes (G1-G4), recent surveillance studies have revealed importance of G9 strains as an aetiological agent of infantile diarrhoea. OBJECTIVE Detection and genotyping of GARVs from children, admitted with gastroenteritis to Dr. B.C. Roy Memorial Hospital for Children, Kolkata, India. STUDY DESIGN GARVs were detected in stool specimens by RNA electrophoresis in polyacrylamide gels. G- and P-genotyping were performed by seminested multiplex PCR assays. VP7 gene of rotavirus G9 and G12 strains were sequenced for further analysis. RESULTS Of 249 GARV strains (n=668, May 2005-December 2006), G- and P-genotyping were successfully accomplished for 197 and 204 samples, respectively. G1 (41.6%) was most prevalent G-genotype followed by G2 (33%), G12 (14.2%), G9 (10.1%) and mixed genotype (1%). Prevalent P-genotypes were P[8] (54.4%), P[4] (31.4%), P[6] (7.3%) and mixed genotype (6.9%). Overall, G1P[8], G2P[4], G9P[8], G12P[8] and G12P[6] were identified as important G-P combinations. Phylogenetic analysis of 13 G9 strains revealed clustering within G9 lineage III. Nine of 28 G12 strains were sequenced and exhibited phylogenetic clustering with previously reported G12 strains from Kolkata. CONCLUSION In comparison to our previous data (2003 to April 2005), G9 and G2P[4] strains established themselves in a short time span as important genotypes in eastern India.

Subtype prevalence, plasmid profiles and growing fluoroquinolone resistance in Shigella from Kolkata, India (2001-2007): a hospital-based study

Objectives  Shigellosis is a major public health problem, and increasing antimicrobial resistance has complicated its treatment. We report isolation frequency, plasmid profiles and antimicrobial resistance of Shigella subtypes in Kolkata, India, from a prospective hospital‐based study.