Genetic diversity of Indian Plasmodium vivax isolates based on the analysis of PvMSP3ß polymorphic marker.

BACKGROUND: Malaria is one of the major communicable diseases in India and worldwide. PvMSP3ß is a highly polymorphic gene due to its large insertions and deletions in the central alanine-rich region, which, in turn, makes it a valuable marker for population genetic analysis. Very few studies are available from India about the genetic diversity of Plasmodium vivax based on PvMSP3ß gene, and hence, this study was designed to understand the molecular diversity of the P. vivax malaria parasite. The accumulating epidemiological data provide insights into the circulating genetic variants of P. vivax in India, and ultimately benefits the vaccine development. MATERIALS AND METHODS: A total of 268 samples confirmed to be positive by microscopy, rapid diagnostic test, and quantitative buffy coat test were collected from four different regions of India (Puducherry, Mangaluru, Jodhpur, and Cuttack) in the present study. Polymerase chain reaction (PCR)-based diagnosis was carried out to confirm the P. vivax monoinfection, and only the mono-infected samples were subjected to PvMSP3ß gene amplification and further restriction fragment length polymorphism (RFLP) to determine suballeles. RESULTS: Based on the size of the amplified fragment, the PvMSP3ß gene was apportioned into two major types, namely Type A genotype (1.6-2 Kb) was predominantly present in 148 isolates and Type B (1-1.5 Kb) was observed in 110 isolates. The percentage of mixed infections by PCR was 3.73%. All the PCR products were subjected to RFLP to categorize into suballeles and we detected 39 suballeles (A1-A39) in Type A, and 23 suballeles (B1-B23) in Type B genotype. A high degree of diversity was observed among the isolates collected from Mangaluru region when compared to isolates collected from other regions. CONCLUSION: The present study showed a high degree of genetic diversity of PvMSP3ß gene among the isolates collected from various parts of India. High polymorphism in PvMSP3ß gene makes it a promising marker for epidemiological and vaccine development studies.

Polymorphisms in genes associated with drug resistance of Plasmodium vivax in India.

Malaria is a sterning public health concern in India and contribute to a major part of malaria burden in Southeast Asia. Being more populated and diverse geographic conditions makes more suitable place for sustaining malaria parasite in India. Anti-malarial resistance is a major concern in the battle against malaria, and the identified molecular markers will aid us to monitor the drug resistance in endemic areas. The aim of the current study is to determine the genotype of drug resistance associated genes pvmdr-1 and pvcrt-o from four different regions of India. Especially from Puducherry and Jodhpur, there were no prior studies focused on screening of drug resistance genes in P. vivax parasite. A total of 240 positive P. vivax infected patient samples were collected from four tertiary care hospitals from four different regions of India, namely, Puducherry (PDY), Mangaluru (MAQ), Cuttack (CTC), Jodhpur (JDH). All samples were screened by microscopy, RDT, QBC, and further DNA was extracted and vivax mono-infection was confirmed by nested PCR. Randomly selected amplicons were further subjected to nucleotide sequencing. The prevalence of K10 insertion in pvcrt-o gene was detected with 18.8% in PDY, 12.5% in MAQ and 6.3% in CTC P. vivax isolates, whereas no change in nucleotide was identified in P. vivax isolates collected from JDH region. Based on the F1076L mutation in pvmdr-1 gene, resistant P. vivax isolates was highly predominant in both the regions, JDH and CTC, with 100%, followed by MAQ with 93.3% and PDY with 73.3%. This study showed less frequency of pvcrt-o and high frequency of pvmdr-1 gene variants associated with CQ resistance, which act as an indicator and the onset of P. vivax drug resistance trend in four different regions of India. Due to the poor phenotypic studies available for P. vivax parasite, the present study data for CQ resistance based on pvcrt-o and pvmdr-1 markers should assist by providing base-line data for future monitoring of drug resistance.

Bacteriological profile of ventilator-associated pneumonia in a tertiary care hospital.

BACKGROUND: Ventilator-associated pneumonia (VAP) is the most frequent intensive care unit (ICU)-acquired infection. The etiology of VAP and their antimicrobial susceptibility pattern varies with different patient populations and types of ICUs. MATERIALS AND METHODS: An observational cross-sectional study was performed over a period of 2 years in a tertiary care hospital to determine the various etiological agents causing VAP and to detect the presence of multidrug-resistant (MDR) pathogens in these VAP patients. Combination disk method, Modified Hodge test, ethylenediaminetetraacetic acid disk synergy test, and AmpC disk test were performed for the detection of extended-spectrum beta-lactamase (ESBL), carbapenemases, metallo-beta-lactamases (MBL), and AmpC beta-lactamases, respectively. RESULTS: The prevalence of VAP was 35%. Enterobacteriaceae (66.66%) and Staphylococcus aureus (20%) were common in early-onset VAP, while nonfermenters (50%) and Enterobacteriaceae (40.61%) were predominant from late-onset VAP. Nearly 60.87% of the bacterial pathogens were MDR. ESBL was produced by 21.74% of Enterobacteriaceae. AmpC ß-lactamase was positive in 35.29% nonfermenters and 26.08% Enterobacteriaceae. MBL was positive in 17.64% nonfermenters and 17.39% Enterobacteriaceae. Among the S. aureus isolates, 75% were cefoxitin resistant. Prior antibiotic therapy (P = 0.001) and hospitalization of 5 days or more (P = 0.001) were independent risk factors for VAP by MDR pathogens. polymyxin B, tigecycline, and vancomycin were the most sensitive drugs for Gram-negative and positive isolates respectively from VAP. STATISTICAL ANALYSIS: SPSS for Windows Version SPSS 17.0 (SPSS Inc., Chicago, IL, USA) and Chi-square with Yates correction. CONCLUSION: Late-onset VAP is increasingly associated with MDR pathogens. Treatment with polymyxin B, tigecycline, and vancomycin should be kept as last-line reserve drugs against most of the MDR pathogens.

Emerging enteric fever due to switching biotype of Salmonella (paratyphi A) in Eastern Odisha.

BACKGROUND: Typhoid fever is classically caused by Salmonella enterica serotype typhi.Recently the frequency of isolation of S. paratyphi A (SPA) has been increased in comparison to S. typhi in Indian scenario. AIM: To observe the rate of isolation and antimicrobial susceptibility pattern of SPA from suspected enteric fever cases attending tertiary care centres of Eastern Orissa. SETTINGS AND DESIGN: Retrospective study Materials and Methods: 1488 blood samples were collected during different duration of fever and cultured in BACTEC blood culture system and bottles showing signal for growth were subcultured and identified as Salmonella spp. by standard procedure and mini API (Biomeriux) and antimicrobial susceptibility by disc diffusion method. STATISTICAL ANALYSIS: Chi square test. RESULTS: 167 Salmonella spp. were isolated including 83.8% Salmonella paratyphi A and 16.6% S. typhi. Among them 102 were males and 65 were females with mean age of 22.7 yrs. S. paratyphi A was the predominant spp. each year but during 2008 - 2011, there was a dramatic rise (significant P value- 0.034). Multidrug resistance was noticed in 10.2% of the isolates. 98% of S. paratyphi A were resistant to nalidixic acid and 41% to ciprofloxacin, but the MIC of ciprofloxacin was raised between 1-2 µgm/dl showing the relation between nalidixic acid resistance and raised MIC of ciprofloxacin. CONCLUSION: Nalidixic acid should be tested along with ciprofloxacin disc while testing for susceptibility and MIC of ciprofloxacin is mandatory before advocating therapy to prevent treatment failure.