Distribution and frequency of common mutations in rpoB gene of Mycobacterium tuberculosis detected by Xpert MTB/RIF and identification of residential areas of rifampicin resistant-TB cases: A first retrospective study from Mizoram, Northeast India.

Background: Rifampicin resistance (RR) is a surrogate marker of multidrug-resistant tuberculosis. The aim of this study is to determine the frequency of the commonly mutated probes for rpoB gene and locate the residential areas of the Rifampicin Resistant-TB (RR-TB) patients in a high endemic zone of Northeast India. Methods: Archived data of 13,454 Xpert MTB/RIF reports were evaluated retrospectively between 2014 and 2021. Socio-demographic and available clinical information were reviewed and analyzed for RR-TB cases only. Logistic Regression was used to analyze the parameters with respect to probe types. P-value ≤ 0.05 was considered to be statistically significant. Results: 2,894 patients had Mycobacterium tuberculosis infection out of which 460 were RR-TB, which was most prevalent among 25-34 years. The most common mutation occurred in probe A (25.9 %) followed by E (23.5 %), D (9.8 %), B (2.6 %) and the least in C (0.2 %). High prevalence (34.3 %) of probe mutation combinations were also found: probes AB (0.4 %), AD (32.8 %), AE (0.4 %), DE (0.2 %) and ADE (0.4 %). Seventeen patients (3.7 %) were found without any missing probes. RR-TB patients were mostly located in Aizawl North -III, South -II and East -II constituencies. Conclusion: This study provides genetic pattern of drug resistance accountable for RR over the past years in Mizoram which will help local clinicians in the initiation of correct treatment. Also, our findings provide a baseline data on the magnitude of RR-TB within the state and identification of the residential areas can help local health authorities in planning surveillance programs to control the spread of RR-TB.

Molecular typing of dengue virus in Mizoram, Northeast India.

INTRODUCTION: Dengue is an emerging vector-borne public health threat and characterization at the molecular level is important for proper management of the disease. The aim of the study is to examine the diversity of the dengue viral serotypes from a hilly mountainous region of Northeast India. METHODOLOGY: Thirty-six blood samples that were positive for dengue virus IgM antibodies identified by the enzyme-linked immunosorbent assay (ELISA) method were collected and quantified for the IL6 gene expression by using reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: All the patients had dengue hemorrhagic fever (DHF); 12 samples had a monotypic infection and 14 samples had dual infection with various dengue virus (DENV) serotypes; one sample had triple infection with DENV-1, DENV-2, and DENV-3. CONCLUSIONS: This study identified DENV-1 as the major serotype in the state of Mizoram and it is the first report on the molecular typing of the dengue virus from the hilly mountainous state located in the Indo-Burma region bordering Myanmar and Bangladesh.

MGIT sensitivity testing and genotyping of drug resistant Mycobacterium tuberculosis isolates from Mizoram, Northeast India.

PURPOSE: Tuberculosis, a crucial infectious disease is still a health concern globally. India is among the countries with high MDR-TB burden. Currently, sputum smear microscopy using Ziehl Neelsen stain and GeneXpert are the only diagnostic means in Mizoram. This study was done to characterize local tuberculosis strains circulating in Mizoram. METHODS: Sputum was cultured using MGIT 960 and DST was performed for Streptomycin, Isoniazid, Rifampicin, Ethambutol and Pyrazinamide. GeneXpert test was done simultaneously. DNA was extracted using Trueprep AUTO v2, molbio diagnostics. Antibiotic Resistance Genes and LSP were amplified and sequenced. RESULTS: Ser315Thr was the most common mutation in katG among MDR-TB isolates. GeneXpert probes A and D drop out upon sequencing showed L511P, H526Q and H526L mutation. The L511P and H526Q mutations were seen in new and treated cases. Discrepancy between MGIT 960 and GeneXpert were observed. LSP-PCR revealed that Indo-Oceanic, East-African Indian, Euro-American and Beijing lineages were found in Mizoram. CONCLUSION: This study provides mutation information on the resistant genotypes detected with GeneXpert as well as MGIT 960. It also provides information on the lineages of Mycobacterium tuberculosis circulating in the state. Utilization of sequencing technologies is essential in diagnostic laboratories to rule out discrepant results and as a cautionary measure to prevent wrong diagnosis and treatment.

Pathogenic microbes contaminating mobile phones in hospital environment in Northeast India: incidence and antibiotic resistance.

BACKGROUND: The present study attempts to identify and determine the pattern of drug susceptibility of the microorganisms present in mobile phones of health care workers (HCWs) and non-HCWs in a hospital environment. Mobile phones of 100 participants including both genders were randomly swabbed from nine different wards/units and the bacterial cultures were characterized using VITEK 2 system. RESULTS: Forty-seven mobile phones were culture positive and a total of 57 isolates were obtained which consisted of 28 Gram-positive organisms and 29 Gram-negative organisms. The predominating organisms were Acinetobacter baumannii and Staphylococcus hominis. Among all the isolates from the mobile phones of HCW and non-HCWs, five isolates had ESBL and three isolates had colistin resistance. Incidentally, MRSA was not found on the mobile phones tested. The isolated organisms showed 100% susceptibility to linezolid, daptomycin, vancomycin, imipenem, meropenem, gentamicin, amikacin, ciprofloxacin and tigecycline, while high resistance was shown against benzylpenicillin (75.0%), cefuroxime and cefuroxime axetil (56.5%). Non-HCWs' mobile phones were more contaminated as compared to HCWs (P = 0.001) and irrespective of individuals' gender or toilet habits, both Gram-positive and Gram-negative organisms were present on the mobile phones. CONCLUSION: This study reports for the first time that the mobile phones of non-health care workers harbour more bacterial diversity and are more prone to cause transmission of pathogens. This study can serve to educate the public on personal hand hygiene practices and on maintaining clean mobile phones through antiseptic measures.

Retrospective audit of the widal test for diagnosis of typhoid Fever in pediatric patients in an endemic region.

INTRODUCTION: Although typhoid fever is confirmed by culture of Salmonella Typhi, Widal test is widely used in India but little information exists about its reliability. MATERIALS AND METHODS: We examined the performance of Widal test in our hospital for diagnosis of typhoid fever in children. Hundred consecutive pediatric in-patients for whom, the Widal test was requested were grouped into four categories: widal positive and clinically consistent with typhoid fever (Group 1; n=42), widal negative but clinically consistent (Group 2, n=12), widal positive but not clinically consistent (Group 3, n=12) and widal negative and also not clinically consistent (Group 4, n=34). The results were analyzed by the test performance criteria, namely, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) using culture-confirmed typhoid fever cases as the "true positives". RESULTS: We found that 7/100 patients had culture-proven typhoid fever. Using a cut off ≥ 50 for O agglutinins or ≥100 for H agglutinins, the Widal test gave a sensitivity of 71.43%, specificity of 47.31%, and a positive predictive value of 09.25% and a negative predictive value of 95.65%. CONCLUSION: The Widal test is an easy, inexpensive and relatively non-invasive but is not reliable in our set up because of a low PPV. There is a need for a more efficient rapid diagnostic test for typhoid fever.