Indian Journal of Medical Microbiology最新文献

{"title":"Accelerating pneumococcal protection in India: The case for rapid adoption of PCV20 across pediatric and adult populations","authors":"Rosemol Varghese ,&nbsp;M. Gurumoorthy ,&nbsp;Greeshma Grace Thomas ,&nbsp;Kamini Walia ,&nbsp;Anil Kumar ,&nbsp;Shariqa Qureshi ,&nbsp;Bijayini Behera ,&nbsp;K.G. Gopinath ,&nbsp;Richa Gupta ,&nbsp;Ruchika Goel ,&nbsp;Ayyanraj Neeravi ,&nbsp;Sulochana Putli Bai ,&nbsp;Balaji Veeraraghavan","doi":"10.1016/j.ijmmb.2025.100893","DOIUrl":"10.1016/j.ijmmb.2025.100893","url":null,"abstract":"<div><h3>Background</h3><div><em>Streptococcus pneumoniae</em> poses a significant public health burden, particularly in India, where invasive and non-invasive forms contribute to high morbidity and mortality. Rapid disease progression and limitations of antimicrobial therapy underscore the need for preventive strategies. Pneumococcal vaccines, especially the 20-valent conjugate vaccine (PCV20), offer robust protection against diverse serotypes, reduce nasopharyngeal carriage, and promote herd immunity.</div></div><div><h3>Objectives</h3><div>To understand the epidemiology of the pneumococcal disease and establish the evidence for the use of higher valent pneumococcal conjugate vaccines in Indian adults.</div></div><div><h3>Content</h3><div>This paper describes the epidemiology of pneumococcal disease, urgency of pneumococcal vaccination, serotype replacement dynamics, and the advantages of PCV20 over PPSV23. In India, delayed vaccine adoption and unique serotype profiles necessitate targeted strategies, including catch-up campaigns and enhanced surveillance, to achieve herd immunity and mitigate the disease burden within 5–10 years.</div></div>","PeriodicalId":13284,"journal":{"name":"Indian Journal of Medical Microbiology","volume":"56 ","pages":"Article 100893"},"PeriodicalIF":1.4,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144309904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carbapenem-resistant Acinetobacter baumannii: prevalence, phenotypic and genotypic analysis in cases of ventilator associated pneumonia from a teaching hospital in Delhi, India","authors":"Sheetal Goenka,&nbsp;Manisha Jain,&nbsp;Wanshisha Wanswett,&nbsp;Poonam Loomba,&nbsp;Abha Sharma,&nbsp;Bibhabati Mishra","doi":"10.1016/j.ijmmb.2025.100894","DOIUrl":"10.1016/j.ijmmb.2025.100894","url":null,"abstract":"<div><h3>Background and objectives</h3><div>The high prevalence of multi drug resistant and carbapenam resistant <em>Acinetobacter baumannii</em>(CRAB)is a serious concern for patient management. The most common mechanism of carbapenamresistance is the presence of different types of carbapenamaseenzymes. The type of carbapenamase present affects the optimization of treatment. In this study, we aimed to investigate the prevalence of carbapenem resistance and characterize the genetic mechanisms associated with antimicrobial resistance in <em>Acinetobacter baumannii</em> isolates.</div></div><div><h3>Materials and methods</h3><div>All clinical isolates of CRAB from ventilator associated pneumonia were included in this study. Clinical, phenotypic, and genotypic data were collected, including clinical details, identification, antimicrobial susceptibility testing, phenotypic detection of carbapenemase activity, biofilm formation assay, and molecular identification of carbapenemase genes like blaOXA-23,blaNDM-1,blaVIM-1 and AmpC.</div></div><div><h3>Result</h3><div>The blaOXA-23-like gene was detected in 97 % (97/100) of CRAB isolates followed by AmpC (21/100,21 %), blaNDM-1(10/100,10 %) and blaVIM-1 in 6 % (6/100) of isolates. The mortality rate among MBL-positive patients was found to be 67 % (65/97). Furthermore, all <em>Acinetobacter baumannii</em> isolates exhibited biofilm-forming capacity, with varying degrees of biofilm production.</div></div><div><h3>Conclusion</h3><div>There is high prevalence of carbapenamase enzymes in CRAB isolates. The high detection of blaOXA-23-like, AmpC, blaNDM-1, and blaVIM-1AmpC underscores the urgency to enforce infection control measures and optimize antimicrobial stewardship practices to prevent cross transmission of the organism. Further presence of biofilm formation in almost all the isolates reiterates the need for innovative strategies to combat persistent infections by this organism.</div></div>","PeriodicalId":13284,"journal":{"name":"Indian Journal of Medical Microbiology","volume":"56 ","pages":"Article 100894"},"PeriodicalIF":1.4,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144288907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unearthing novel mutations and genetic variation in drug sensitive and resistant isolates of Mycobacterium tuberculosis through whole genome sequencing: A study from eastern Uttar Pradesh, India","authors":"Kamal Singh ,&nbsp;Saravanan Vijayakumar ,&nbsp;Swati Sharma ,&nbsp;Shampa Anupurba","doi":"10.1016/j.ijmmb.2025.100895","DOIUrl":"10.1016/j.ijmmb.2025.100895","url":null,"abstract":"<div><h3>Purpose</h3><div>Drug-resistant tuberculosis (DR-TB) presents a formidable public health challenge worldwide. Therefore, this study was conducted to elucidate the complete genetic profiles of drug-sensitive (DS), and drug-resistant TB isolates using Whole Genome Sequencing (WGS).</div></div><div><h3>Methods</h3><div>The study includes a set of sputum specimens containing five DS-TB, multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) from distinct individuals. The identification and susceptibility was confirmed using GeneXpert assay, GenoType MTBDR plus assay, and GenoTypeMTBDR<em>sl</em> assay. Furthermore, specimens were cultured using the BD BACTEC MGIT 960 and subsequently confirmed through Capilia rapid kit. WGS was employed for the identification of Single Nucleotide Polymorphisms (SNPs), <em>Mycobacterium tuberculosis</em> complex (MTBC) lineages, and spoligotypes. The <em>H37Rv</em> was used as a positive control.</div></div><div><h3>Results</h3><div>The findings of WGS showed, all the MDR-TB and XDR-TB isolates exhibited non-synonymous mutation (Ser450Leu, Gln432Leu, and His445Gln) within the <em>rpoB</em> gene. The isolates were simultaneously harboring mutations at <em>fab</em>G1-8T &gt; C, <em>fab</em>G1-17G &gt; T, <em>fab</em>G1-15C &gt; T, and <em>inhA</em>-154G &gt; A. One DS-TB isolate was carrying resistance mutations in the rrs gene at position 517C &gt; T, while three MDR-TB isolates turned out to be pre-XDR-TB carrying mutations associated with fluoroquinolone (FQ) resistance (<em>gyrA</em> Ala90Val, <em>gyrA</em> Asp94His, and <em>gyrA</em> Asp94 Gly). The study reports novel mutations <em>pncA</em>391dupG and for the first time mutation in <em>thyX</em> gene in clinical isolates of MTBC. Most of the MDR/XDR-TB isolates were predominantly associated with the Beijing sub-lineage within the East Asian Lineage 2.</div></div><div><h3>Conclusions</h3><div>In conclusion, our study highlighted the challenges surrounding the rapid identification and essential information regarding the genetic diversity of TB strains which contribute valuable insights into the TB epidemiology.</div></div>","PeriodicalId":13284,"journal":{"name":"Indian Journal of Medical Microbiology","volume":"56 ","pages":"Article 100895"},"PeriodicalIF":1.4,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adult cutaneous diphtheria by non-toxicogenic strain: Case report and review of literature","authors":"Khyati ,&nbsp;Benu Dhawan ,&nbsp;Vikas Gautam ,&nbsp;Nishant Shekhar ,&nbsp;Neetu Bhari ,&nbsp;Jaya Biswas ,&nbsp;Pranav Rai ,&nbsp;Ritika Dhakad ,&nbsp;Bimal Kumar Das","doi":"10.1016/j.ijmmb.2025.100892","DOIUrl":"10.1016/j.ijmmb.2025.100892","url":null,"abstract":"<div><div>We report an unusual case of recurrently infected post-folliculitis keloid. The diagnosis of cutaneous diphtheria was made by isolation of <em>Corynebacterium diphtheriae</em> cultured from pus collected from the skin lesion. The strain was non-toxigenic on multiplex real-time PCR assay. A prior pus sample from the lesion had grown Methicillin resistant <em>Staphylococcus aureus</em> (MRSA). The patient was treated with oral erythromycin for 14-days. Chemoprophylaxis was advised to the close contacts. The present case emphasizes the importance of investigation for unusual etiologies in patients with non-responding ulcerative cutaneous lesions. Early diagnosis of cutaneous diphtheria is required for appropriate treatment and effective control measures.</div></div>","PeriodicalId":13284,"journal":{"name":"Indian Journal of Medical Microbiology","volume":"56 ","pages":"Article 100892"},"PeriodicalIF":1.4,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144255329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterologous interference between Mayaro and Chikungunya viruses in Vero cells","authors":"Mauricio Gabriel E.L. Silva ,&nbsp;Karla Fabiane L. Melo ,&nbsp;Samir M.M. Casseb ,&nbsp;Eliana V.P. Silva ,&nbsp;Ana Cecília R. Cruz ,&nbsp;Carlos Alberto M. Carvalho","doi":"10.1016/j.ijmmb.2025.100891","DOIUrl":"10.1016/j.ijmmb.2025.100891","url":null,"abstract":"<div><h3>Purpose</h3><div>Mayaro virus (MAYV) and Chikungunya virus (CHIKV) are arthritogenic alphaviruses with distinct natural vectors but common vertebrate hosts, whose concomitant circulation in Central and South America provides opportunities for mixed infections in humans. In view of this, we aimed to investigate the heterologous interference between these arboviruses during coinfections and superinfections in a primate cell line.</div></div><div><h3>Methods</h3><div>Experimental infections with MAYV and CHIKV were performed singly, simultaneously or consecutively, and cytopathic effect, cell viability and virus load were assessed by phase contrast light microscopy, fluorimetry and reverse transcription-quantitative polymerase chain reaction, respectively.</div></div><div><h3>Results</h3><div>All infection schemes led to a strong cytopathic effect accompanied by an average reduction of almost 90 % in cell viability within 24 h post-infection. Although there was no statistically significant difference between the loads of both viruses in coinfections, a decrease in the individual virus load of more than 90 % when compared to their respective single infections was observed. Furthermore, superinfections resulted in widely significant differences in the amount of progeny formed for each virus, with a first-mover advantage regardless of the species.</div></div><div><h3>Conclusions</h3><div>MAYV and CHIKV are subject to heterologous interference during coinfections and superinfections in primate cells, which could possibly impact disease outcome in humans.</div></div>","PeriodicalId":13284,"journal":{"name":"Indian Journal of Medical Microbiology","volume":"56 ","pages":"Article 100891"},"PeriodicalIF":1.4,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of human Metapneumovirus infections in Mumbai (2017–2024)","authors":"Aruna Poojary ,&nbsp;Anurag Kumar Bari ,&nbsp;Seema Rohra","doi":"10.1016/j.ijmmb.2025.100890","DOIUrl":"10.1016/j.ijmmb.2025.100890","url":null,"abstract":"","PeriodicalId":13284,"journal":{"name":"Indian Journal of Medical Microbiology","volume":"56 ","pages":"Article 100890"},"PeriodicalIF":1.4,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"HIV vaccine – Is there a ray of hope in the rugged journey?","authors":"Gautam Barik,&nbsp;Gnanadurai John Fletcher,&nbsp;Diviya Alex,&nbsp;John Paul Demosthenes,&nbsp;Priya Abraham,&nbsp;Rajesh Kannangai","doi":"10.1016/j.ijmmb.2025.100885","DOIUrl":"10.1016/j.ijmmb.2025.100885","url":null,"abstract":"<div><h3>Background</h3><div>The path of HIV vaccine development is riddled with numerous challenges. The high mutation and recombination rate of the virus, the establishment of a viral reservoir early in infection, and the failure to mount an effective immune response have added to the complexities of vaccine development.</div></div><div><h3>Objective</h3><div>In this review, we tried to revisit the vaccine development efforts, categorize the immunogens based on the immune response they tried to elicit and discuss the limited success or failure they achieved so far.</div></div><div><h3>Content</h3><div>The initial efforts of vaccine development concentrated on a three-pronged approach, induction of neutralizing antibodies, induction of cell-mediated immunity, or a combination of the two. Since then, the efforts to develop an effective immunogen have come a long way through the usage of poxviral vectors, conserved immunogens, and mosaic immunogens to the current trend of using mRNA-based vaccines, engineered outer domains on scaffold proteins and the development of germline targeting immunogens for induction of broadly neutralizing antibody-producing B-cell lineage. We also tried to narrate the current trends and the future directions of HIV vaccine development.</div></div>","PeriodicalId":13284,"journal":{"name":"Indian Journal of Medical Microbiology","volume":"56 ","pages":"Article 100885"},"PeriodicalIF":1.4,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144230194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Varied synergistic activity of colistin and polymyxin B with meropenem, rifampicin and tigecycline: An in vitro study on carbapenem resistant Acinetobacter baumannii from India","authors":"Manasa Tantry ,&nbsp;Muralidhar Varma ,&nbsp;Shwethapriya Rao ,&nbsp;Chiranjay Mukhopadhyay ,&nbsp;Vandana Kalwaje Eshwara","doi":"10.1016/j.ijmmb.2025.100889","DOIUrl":"10.1016/j.ijmmb.2025.100889","url":null,"abstract":"<div><h3>Purpose</h3><div>Effective therapeutic choices for infections by carbapenem resistant <em>Acinetobacter baumannii</em> (CRAB) in resource constrained settings is limited. Prospective antimicrobial combinations with polymyxins, need to be tested for synergy to mitigate further development of resistance. This study evaluates the synergistic effects of colistin and polymyxin B combined with meropenem, rifampicin, and tigecycline against CRAB isolates from bloodstream infections.</div></div><div><h3>Methods</h3><div>Twenty-five epidemiologically distinct CRAB strains were included. The minimum inhibitory concentrations (MICs) of the antimicrobials were determined by broth microdilution. The synergistic activities of the antimicrobial combinations were evaluated by checkerboard broth microdilution (CBM). Antimicrobials were tested at concentrations from 4 to 8 times down to 1/8–1/16 of their expected MIC, with a final inoculum of 10⁵ CFU/mL. The antimicrobial combinations that demonstrated greater synergistic activity were confirmed using the time-kill assay (TKA).</div></div><div><h3>Results</h3><div>None of the strains were resistant to polymyxins (MIC ≤4 mg/L). Colistin-meropenem, colistin-rifampicin and colistin-tigecycline combinations achieved superior synergy over the polymyxin B-meropenem, polymyxin B-rifampicin and polymyxin B-tigecycline combinations (<em>P</em>=&lt;0.001, <em>P</em> = 0.03, and <em>P</em> = 0.01, respectively) in the CBM assay. In the TKA, combinations of colistin (0.1–0.5 mg/L) with subinhibitory concentrations of meropenem (4–8 mg/L), rifampicin (1–4 mg/L), and tigecycline (0.06–0.25 mg/L) exhibited synergistic and bactericidal activity against a subset of isolates at 24 h.</div></div><div><h3>Conclusions</h3><div>Significant concordance between the CBM and TKA was observed. Our findings suggest that subinhibitory antimicrobial concentrations in combinations can improve therapeutic efficacy and minimize polymyxin side effects. Additionally, in vivo studies are warranted to optimize the combinational therapy.</div></div>","PeriodicalId":13284,"journal":{"name":"Indian Journal of Medical Microbiology","volume":"56 ","pages":"Article 100889"},"PeriodicalIF":1.4,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144203310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The importance of stool antigen test in the diagnosis and management of Helicobacter pylori infections","authors":"Ruma Das,&nbsp;Hitender Gautam,&nbsp;Priyam Batra,&nbsp;Bimal K. Das","doi":"10.1016/j.ijmmb.2025.100888","DOIUrl":"10.1016/j.ijmmb.2025.100888","url":null,"abstract":"","PeriodicalId":13284,"journal":{"name":"Indian Journal of Medical Microbiology","volume":"56 ","pages":"Article 100888"},"PeriodicalIF":1.4,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144208426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Black swimming dots in cell culture: first report of Bradyrhizobium as a cause","authors":"Jasleen Kaur,&nbsp;Manisha Biswal","doi":"10.1016/j.ijmmb.2025.100887","DOIUrl":"10.1016/j.ijmmb.2025.100887","url":null,"abstract":"<div><h3>Introduction</h3><div>Black swimming dots (BSDs) are a frequent concern for scientists performing cell culture experiments. Despite this, there is very limited literature on this phenomenon. There is one report of <em>Achromobacter</em> species as the causative organism of black swimming dots in cell culture. In this study, we have revealed a 16S ribosomal RNA (bacterial rrs gene) full gene-based confirmation of black swimming dots as <em>Bradyrhizobium</em> species in our cell culture experiments. <em>Bradyrhizobium</em> is primarily a soil-dwelling bacteria, carrying out nitrogen fixation in legume roots.</div></div><div><h3>Methodology</h3><div>After inoculating the patient blood in L929 cell lines, DNA (deoxyribonucleic acid) isolation was performed on the seventh day from the trypsinized L929 cells. The culture flask under the tissue culture inverted microscope showed small moving dots in the field. The DNA extracted from the infected cell culture was then subjected to conventional PCR (Polymerase Chain Reaction) with the three sets of pan-bacterial primers targeting the full-length 16S ribosomal RNA gene.</div></div><div><h3>Results</h3><div>Our study reveals the contamination of mammalian cell culture with the black swimming dots caused by <em>Bradyrhizobium</em> species bacteria.</div></div><div><h3>Conclusion</h3><div>The 16S rRNA full gene analysis revealed that the black swimming dots in our cell culture flasks were due to <em>Bradyrhizobium</em> species. This study further clarifies that the BSDs in cell culture caused due to <em>Bradyrhizobium</em> species could not be cleared by 10 μg/ml concentration of both the antibiotics, piperacillin and ciprofloxacin.</div></div>","PeriodicalId":13284,"journal":{"name":"Indian Journal of Medical Microbiology","volume":"56 ","pages":"Article 100887"},"PeriodicalIF":1.4,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144198907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}