Dr. Rama Chaudhry has done her MBBS from LHMC and MD from AIIMS, New Delhi. She is professor and Head in the Department of Microbiology at AIIMS, New Delhi. She is an ASM International Ambassador to India
Background The modern advances in the fields of Medicine and Surgery depend entirely on our abili... more Background The modern advances in the fields of Medicine and Surgery depend entirely on our ability to treat and prevent infections. However, the rising incidence of antimicrobial resitance in both community and hospital settings has proved to be increasingly challenging. In 2017, WHO published a list of ‘priority pathogens’; antibiotic-resistant bacteria which posed the greatest threat to human health. Among them, A. baumannii was recognized as a critical priority pathogen due to its significant role in nosocomial infections. There was a growing call for new avenues in antimicrobial therapy. One such endeavour was to revisit an old therapeutic option against MDRO, viz. bacteriophage therapy. Numerous instances of successful phage therapy have already been published, with many more becoming available each day. Methods A total of fifty (50) multidrug resistant isolates of A. baumannii were collected. We attempted to isolate bacteriophages from hospital sewage water, against these col...
Reinfections due to SARS-CoV-2 have been reported from several countries. Repeat positive RT-PCR ... more Reinfections due to SARS-CoV-2 have been reported from several countries. Repeat positive RT-PCR reports of COVID-19 could be attributed to reinfections or reactivations. Several studies have reported repeat positives. Our study discusses a case series of patients with chronic immunosuppressive illness, who had repeat positive RT-PCR for COVID-19, detected as reinfection and reactivation on whole-genome sequencing.
Purpose: The purpose of this study is to determine the antimicrobial susceptibility pattern, sero... more Purpose: The purpose of this study is to determine the antimicrobial susceptibility pattern, serotype distribution and sequence type (ST) of Streptococcus pneumoniae isolates from invasive and non-invasive infection and correlate it with isolates from commensal nasopharyngeal flora to ascertain their role in infection. Materials and Methods: S. pneumoniae isolates from blood, cerebrospinal fluid, pleural fluid and respiratory secretions (sputum, bronchoalveolar lavage and nasopharyngeal swab/throat swab) were analysed to determine ST, serotype and antimicrobial susceptibility pattern. Serotyping was performed by multiplex polymerase chain reactions as well as by quellung reaction. Antimicrobial susceptibility testing was determined using Kirby Bauer's disc diffusion method as per the Clinical Laboratory Standards Institute guidelines. Minimum inhibitory concentration was determined using E-test for penicillin. Multilocus sequence typing (MLST) was done to understand genetic relatedness and evolutionary relationship among strains. Results: A total of 125 S. pneumoniae isolates were collected, including 25 from invasive pneumococcal disease, 25 from non-invasive and 75 from nasopharyngeal swab of healthy children (Commensal). Resistance to penicillin, erythromycin, and co-trimoxazole was observed in 14.4%, 12% and 81.6% of the isolates, respectively, by KirbyBauer's disc diffusion method. Serotype 14 was found to be the most prevalent in invasive and non-invasive isolates, while serotype 6 was the most common in commensal isolates. New STs were found among invasive (ST13826, ST13827), non-invasive (ST13823, ST13824, and ST13961) and commensal (ST13825) isolates. Conclusion: MLST sequence analysis shows that invasive isolates were found to be clustered with non-invasive and commensal isolates. Analysis of MLST suggests the possibility of genetic relatedness and exchange of genetic material between invasive, non-invasive and commensal isolates.
Background: Neutropenic enterocolitis (NEC) is a dreaded complication of chemotherapy. There is s... more Background: Neutropenic enterocolitis (NEC) is a dreaded complication of chemotherapy. There is scant literature regarding incidence, clinical features, and determinants. The understanding of gut dysbiosis in NEC and pediatric cancer is evolving. Methods: Pediatric cancer patients with neutropenia and gastrointestinal symptoms were evaluated for NEC with contrast-enhanced computed tomography abdomen. Clinical, imaging, and laboratory features were analyzed. Fecal samples were analyzed for fecal calprotectin by sandwich enzyme-linked immunoassay and gut microbiota by conventional culture and compared with healthy controls and children without NEC. Results: NEC was diagnosed in 44 children based on clinical and imaging features with incidence of 7.4% (4 had recurrent episodes). Common manifestations included fever (98%), pain abdomen (88%), and diarrhea (83%). Hypoalbuminemia was observed in 78% of patients. Large bowel involvement (94%) with diffuse bowel involvement (63%) and pancol...
Introduction: Increasing occurrence of infections caused by multidrug-resistant Gram-negative bac... more Introduction: Increasing occurrence of infections caused by multidrug-resistant Gram-negative bacteria resulted in colistin being the last agent for treatment. Apart from plasmid-mediated mcr genes, mutations involving several genes like mgrB, phoP/phoQ, pmrA, pmrB, pmrC, and crrABC genes, are leading causes of colistin resistance. Four colistin susceptibility testing methods were compared against broth microdilution (BMD) and determined the presence of the mcr1-5 gene. Methodology: A total of 100 carbapenem-resistant Enterobacterales isolates were tested for colistin susceptibility by commercial broth microdilution (cBMD), E-test, VITEK-2, and rapid polymyxin NP assay (RPNP) and compared with BMD. The presence of the mcr1-5 gene was determined by modified RPNP and PCR. Two non- mcr colistin-resistant XDR isolates were subjected to whole-genome sequencing using Illumina MiSeq sequencing platform. Results: Among 100 carbapenem-resistant Enterobacterales isolates, 15% were resistant t...
We report co-infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Myco... more We report co-infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Mycoplasma pneumoniae in a patient with pneumonia in India. Atypical bacterial pathogens causing community-acquired pneumonia may share similar clinical presentations and radiographic features with SARS-CoV-2 making a thorough differential diagnosis essential. The co-infection of SARS-CoV-2 and M. pneumoniae is infrequently reported in the literature. Broader testing for common respiratory pathogens should be performed in severe COVID-19 cases to rule out other concurrent infections. Early identification of co-existing respiratory pathogens could provide pathogen-directed therapy, and can save patient lives during the ongoing COVID-19 outbreak.
Anaerobic infections are common yet life-threatening. They are being recovered from all sites of ... more Anaerobic infections are common yet life-threatening. They are being recovered from all sites of the body, including the cardiovascular system. This study was aimed to determine the retrospective analysis on the isolation of anaerobes in cardiovascular samples received for a decade-long duration. It helps in knowing the frequency of isolation of anaerobic causes of cardiovascular infection. All cardiovascular samples from the department of Cardio-thoracic vascular surgery from January 2010 to December 2020 were studied. Of 601 samples received, predominant samples were vegetations and valvular tissues of 258, followed by 98 samples of pericardial tissues, 92 samples of embolus, 90 samples of blood and post-operative collections, and 63 excised aneurysms and vascular grafts. Of the total, 15 samples grew anaerobes where Clostridium species were the predominant isolates. Clostridioides difficile was isolated in 2 samples. Anaerobes in cardiovascular samples are uncommon yet form a significant cause of morbidity and mortality. Most infections are from the contiguous spread, penetrating trauma, and hematogenous causing endocarditis or valvular infections. These conditions and samples form the seat of infectious focus and clinical suspicion towards the anaerobic cause of these conditions, especially in conventional routine culture-negative samples. Timely diagnosis of anaerobic infections plays a vital role in the good prognostic outcome of patients undergoing cardiothoracic and vascular surgery.
Asian Journal of Research in Infectious Diseases, 2021
Aims: The study aims to compare the clinical and microbiological profile in adult, hospitalised p... more Aims: The study aims to compare the clinical and microbiological profile in adult, hospitalised patients of community acquired pneumonia due to Mycoplasma pneumoniae (MP) vs other bacterial agents. Study Design: Prospective, observational study. Place and Duration of Study: Study was carried out in Department of Microbiology, Kasturba Medical College, Manipal in a span of eighteen months (August 2014 to February 2016). Methodology: A Hospital based study in a tertiary care center was conducted. Adult hospitalised patients suspected of community acquired pneumonia (according to IDSA guidelines) were included in the study. Cases with immunosuppression and prior hospital admission were excluded. Respiratory samples were collected and cultured for all the studied cases. PCR was performed for the detection of Mycoplasma pneumoniae by targeting P1 gene. Results: The study cases (n=140) had mean age of 57 years and mean hospital stay of 7 days, comprising 67.6% males and 32.4% females. ...
Background: The rising incidence of obesity is one of the most serious public health issues in th... more Background: The rising incidence of obesity is one of the most serious public health issues in the developed as well as in developing countries like India. Obesity and overweight are most important risk factors for many chronic diseases, including cardiovascular diseases, diabetes and cancer. In this study the body mass index (BMI) cut off was taken as 18.5-22.9 kg/m2 for normal, 23.0-24.9 kg/m2 for Overweight and >25 kg/m2 for obese as per WHO recommendation for Asian Indians, which is different for developed and developing countries. Role of gut microbiota mediated immune response in the development of obesity has been studied but the literature on Indian population are lacking. Therefore, a study was conducted to determine Toll like receptors (TLRs) in response to human gut microbiota of Indian obese and lean individuals using viable colonocytes in a Non invasive technique and Flowcytometry. Methods: A total of 20 healthy volunteer (10 obese and 10 lean) were enrolled in the study as per inclusion and exclusion criteria. Viable colonocytes were isolated from fecal samples using a Non invasive technique (SCSR Method). Toll like receptors (TLRs) and immunoglobulin (IgA &IgG) receptor concentration were measured by standard Flowcytometry methods using specific fluorochrome conjugated antibodies. Results: Average TLR2 receptor concentration was significantly higher in obese (6.35 %) as compared to lean (2.9 %) (P = 0.01). TLR4 receptor concentration was 1.4 % in obese and 1.65 % in lean although the difference was not statistically significant (P = 0.59). IgA & IgG receptor concentration was 49.6 % & 11.2 % in the obese and 67.15 % & 8.05 % in the lean respectively but the differences among both the group were not statistically significant. Conclusion: The results of the present study will be helpful for physicians and researchers to find some biomarkers which can determine predisposition of the obesity in Indian population and helps to use alternative therapeutics such as probiotics to maintain gut homeostasis and immune modulation to prevent obesity.
Background: We determined the magnitude and clinico-microbiological profile of prosthetic joint i... more Background: We determined the magnitude and clinico-microbiological profile of prosthetic joint infection (PJI) at a tertiary hospital. The diagnostic potential of 16S rRNA gene polymerase chain reaction (PCR) and sequencing on periprosthetic tissue samples was evaluated for the diagnosis of PJI. Materials and Methods: This ambispective cohort study consisted of patients who underwent primary or revision hip or knee arthroplasty from June 2013 to June 2017. The patients were classified as either infected or noninfected according to criteria set out by the musculoskeletal infection society (MSIS). Three to five periprosthetic tissue samples were collected from each patient for culture and 16S rRNA gene PCR sequencing. Results: Hundred and six patients were diagnosed to have PJI as per the MSIS Criteria. The cumulative incidence of PJI at our Institute at the end of 36 months was 1.1% (95% confidence interval [CI]: 0.59–2.91). Microorganisms were isolated by periprosthetic tissue culture (PTC) in 84 patients (sensitivity: 79% and specificity: 100%). Gram-negative aerobes were most frequently isolated (61%). Polymicrobial infections were present in 8.3% of cases. The most common infecting microorganism was Staphylococcus aureus (19.5%). Multidrug resistance and methicillin resistance were noted in 54% and 34% of bacterial isolates, respectively. The sensitivity and specificity of 16S rRNA PCR of periprosthetic tissue was 86% (95% CI: 74.9–89.9) and 100% (95% CI: 94.7–100), respectively. Periprosthetic tissue 16S rRNA PCR was more sensitive than PTC (P = 0.008), although both were 100% specific (P = 0.99). Conclusions: The incidence of PJI at our Institute compares well with other published reports. Contrary to previous reports, a predominance of Gram-negative PJI's was found. The preponderance of multidrug-resistant organisms in PJI's is worrisome. The high sensitivity and specificity of the 16S PCR assay used in our study support its use in culture-negative PJI suspected cases.
Mycoplasma pneumoniae is known to be a major cause of lower respiratory tract infections (LRTIs) ... more Mycoplasma pneumoniae is known to be a major cause of lower respiratory tract infections (LRTIs) in children. We studied 75 children who had been hospitalized for community-acquired LRTIs for the detection of M. pneumoniae by serological analysis and polymerase chain reaction (PCR) to amplify a 277-base pair region of 16S rDNA gene of M. pneumoniae applied to throat swab specimens. Serological and/or PCR positive results diagnosed M. pneumoniae infection in 23 (30.7%) patients.
The authors describe a case series of co-infection with COVID-19 and scrub typhus in two Indian p... more The authors describe a case series of co-infection with COVID-19 and scrub typhus in two Indian patients. Clinical features like fever, cough, dyspnea and altered sensorium were common in both patients. Case 1 had lymphopenia, elevated IL-6 and history of hypertension, while case 2 had leukocytosis and an increased liver enzymes. Both patients had hypoalbuminemia and required admission to the intensive care unit; one of them succumbed to acute respiratory distress syndrome further complicated by multiple organ dysfunction syndrome. Seasonal tropical infections in COVID-19 patients in endemic settings may lead to significant morbidity and mortality. Therefore, high clinical suspicion and an early diagnosis for co-infections among COVID-19 patients are essential for better patient management.
SARS-CoV-2 evolution has continued to generate variants, responsible for new pandemic waves local... more SARS-CoV-2 evolution has continued to generate variants, responsible for new pandemic waves locally and globally. Varying disease presentation and severity has been ascribed to inherent variant characteristics and vaccine immunity. This study analyzed genomic data from 305 whole genome sequences from SARS-CoV-2 patients before and through the third wave in India. Delta variant was responsible for disease in patients without comorbidity(97%), while Omicron BA.2 caused disease primarily in those with comorbidity(77%). Tissue adaptation studies brought forth higher propensity of Omicron variants to bronchial tissue than lung, contrary to observation in Delta variants from Delhi. Study of codon usage pattern distinguished the prevalent variants, clustering them separately, Omicron BA.2 isolated in February grouped away from December strains, and all BA.2 after December acquired a new mutation S959P in ORF1b (44.3% of BA.2 in the study) indicating ongoing evolution. Loss of critical spik...
Background The modern advances in the fields of Medicine and Surgery depend entirely on our abili... more Background The modern advances in the fields of Medicine and Surgery depend entirely on our ability to treat and prevent infections. However, the rising incidence of antimicrobial resitance in both community and hospital settings has proved to be increasingly challenging. In 2017, WHO published a list of ‘priority pathogens’; antibiotic-resistant bacteria which posed the greatest threat to human health. Among them, A. baumannii was recognized as a critical priority pathogen due to its significant role in nosocomial infections. There was a growing call for new avenues in antimicrobial therapy. One such endeavour was to revisit an old therapeutic option against MDRO, viz. bacteriophage therapy. Numerous instances of successful phage therapy have already been published, with many more becoming available each day. Methods A total of fifty (50) multidrug resistant isolates of A. baumannii were collected. We attempted to isolate bacteriophages from hospital sewage water, against these col...
Reinfections due to SARS-CoV-2 have been reported from several countries. Repeat positive RT-PCR ... more Reinfections due to SARS-CoV-2 have been reported from several countries. Repeat positive RT-PCR reports of COVID-19 could be attributed to reinfections or reactivations. Several studies have reported repeat positives. Our study discusses a case series of patients with chronic immunosuppressive illness, who had repeat positive RT-PCR for COVID-19, detected as reinfection and reactivation on whole-genome sequencing.
Purpose: The purpose of this study is to determine the antimicrobial susceptibility pattern, sero... more Purpose: The purpose of this study is to determine the antimicrobial susceptibility pattern, serotype distribution and sequence type (ST) of Streptococcus pneumoniae isolates from invasive and non-invasive infection and correlate it with isolates from commensal nasopharyngeal flora to ascertain their role in infection. Materials and Methods: S. pneumoniae isolates from blood, cerebrospinal fluid, pleural fluid and respiratory secretions (sputum, bronchoalveolar lavage and nasopharyngeal swab/throat swab) were analysed to determine ST, serotype and antimicrobial susceptibility pattern. Serotyping was performed by multiplex polymerase chain reactions as well as by quellung reaction. Antimicrobial susceptibility testing was determined using Kirby Bauer's disc diffusion method as per the Clinical Laboratory Standards Institute guidelines. Minimum inhibitory concentration was determined using E-test for penicillin. Multilocus sequence typing (MLST) was done to understand genetic relatedness and evolutionary relationship among strains. Results: A total of 125 S. pneumoniae isolates were collected, including 25 from invasive pneumococcal disease, 25 from non-invasive and 75 from nasopharyngeal swab of healthy children (Commensal). Resistance to penicillin, erythromycin, and co-trimoxazole was observed in 14.4%, 12% and 81.6% of the isolates, respectively, by KirbyBauer's disc diffusion method. Serotype 14 was found to be the most prevalent in invasive and non-invasive isolates, while serotype 6 was the most common in commensal isolates. New STs were found among invasive (ST13826, ST13827), non-invasive (ST13823, ST13824, and ST13961) and commensal (ST13825) isolates. Conclusion: MLST sequence analysis shows that invasive isolates were found to be clustered with non-invasive and commensal isolates. Analysis of MLST suggests the possibility of genetic relatedness and exchange of genetic material between invasive, non-invasive and commensal isolates.
Background: Neutropenic enterocolitis (NEC) is a dreaded complication of chemotherapy. There is s... more Background: Neutropenic enterocolitis (NEC) is a dreaded complication of chemotherapy. There is scant literature regarding incidence, clinical features, and determinants. The understanding of gut dysbiosis in NEC and pediatric cancer is evolving. Methods: Pediatric cancer patients with neutropenia and gastrointestinal symptoms were evaluated for NEC with contrast-enhanced computed tomography abdomen. Clinical, imaging, and laboratory features were analyzed. Fecal samples were analyzed for fecal calprotectin by sandwich enzyme-linked immunoassay and gut microbiota by conventional culture and compared with healthy controls and children without NEC. Results: NEC was diagnosed in 44 children based on clinical and imaging features with incidence of 7.4% (4 had recurrent episodes). Common manifestations included fever (98%), pain abdomen (88%), and diarrhea (83%). Hypoalbuminemia was observed in 78% of patients. Large bowel involvement (94%) with diffuse bowel involvement (63%) and pancol...
Introduction: Increasing occurrence of infections caused by multidrug-resistant Gram-negative bac... more Introduction: Increasing occurrence of infections caused by multidrug-resistant Gram-negative bacteria resulted in colistin being the last agent for treatment. Apart from plasmid-mediated mcr genes, mutations involving several genes like mgrB, phoP/phoQ, pmrA, pmrB, pmrC, and crrABC genes, are leading causes of colistin resistance. Four colistin susceptibility testing methods were compared against broth microdilution (BMD) and determined the presence of the mcr1-5 gene. Methodology: A total of 100 carbapenem-resistant Enterobacterales isolates were tested for colistin susceptibility by commercial broth microdilution (cBMD), E-test, VITEK-2, and rapid polymyxin NP assay (RPNP) and compared with BMD. The presence of the mcr1-5 gene was determined by modified RPNP and PCR. Two non- mcr colistin-resistant XDR isolates were subjected to whole-genome sequencing using Illumina MiSeq sequencing platform. Results: Among 100 carbapenem-resistant Enterobacterales isolates, 15% were resistant t...
We report co-infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Myco... more We report co-infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Mycoplasma pneumoniae in a patient with pneumonia in India. Atypical bacterial pathogens causing community-acquired pneumonia may share similar clinical presentations and radiographic features with SARS-CoV-2 making a thorough differential diagnosis essential. The co-infection of SARS-CoV-2 and M. pneumoniae is infrequently reported in the literature. Broader testing for common respiratory pathogens should be performed in severe COVID-19 cases to rule out other concurrent infections. Early identification of co-existing respiratory pathogens could provide pathogen-directed therapy, and can save patient lives during the ongoing COVID-19 outbreak.
Anaerobic infections are common yet life-threatening. They are being recovered from all sites of ... more Anaerobic infections are common yet life-threatening. They are being recovered from all sites of the body, including the cardiovascular system. This study was aimed to determine the retrospective analysis on the isolation of anaerobes in cardiovascular samples received for a decade-long duration. It helps in knowing the frequency of isolation of anaerobic causes of cardiovascular infection. All cardiovascular samples from the department of Cardio-thoracic vascular surgery from January 2010 to December 2020 were studied. Of 601 samples received, predominant samples were vegetations and valvular tissues of 258, followed by 98 samples of pericardial tissues, 92 samples of embolus, 90 samples of blood and post-operative collections, and 63 excised aneurysms and vascular grafts. Of the total, 15 samples grew anaerobes where Clostridium species were the predominant isolates. Clostridioides difficile was isolated in 2 samples. Anaerobes in cardiovascular samples are uncommon yet form a significant cause of morbidity and mortality. Most infections are from the contiguous spread, penetrating trauma, and hematogenous causing endocarditis or valvular infections. These conditions and samples form the seat of infectious focus and clinical suspicion towards the anaerobic cause of these conditions, especially in conventional routine culture-negative samples. Timely diagnosis of anaerobic infections plays a vital role in the good prognostic outcome of patients undergoing cardiothoracic and vascular surgery.
Asian Journal of Research in Infectious Diseases, 2021
Aims: The study aims to compare the clinical and microbiological profile in adult, hospitalised p... more Aims: The study aims to compare the clinical and microbiological profile in adult, hospitalised patients of community acquired pneumonia due to Mycoplasma pneumoniae (MP) vs other bacterial agents. Study Design: Prospective, observational study. Place and Duration of Study: Study was carried out in Department of Microbiology, Kasturba Medical College, Manipal in a span of eighteen months (August 2014 to February 2016). Methodology: A Hospital based study in a tertiary care center was conducted. Adult hospitalised patients suspected of community acquired pneumonia (according to IDSA guidelines) were included in the study. Cases with immunosuppression and prior hospital admission were excluded. Respiratory samples were collected and cultured for all the studied cases. PCR was performed for the detection of Mycoplasma pneumoniae by targeting P1 gene. Results: The study cases (n=140) had mean age of 57 years and mean hospital stay of 7 days, comprising 67.6% males and 32.4% females. ...
Background: The rising incidence of obesity is one of the most serious public health issues in th... more Background: The rising incidence of obesity is one of the most serious public health issues in the developed as well as in developing countries like India. Obesity and overweight are most important risk factors for many chronic diseases, including cardiovascular diseases, diabetes and cancer. In this study the body mass index (BMI) cut off was taken as 18.5-22.9 kg/m2 for normal, 23.0-24.9 kg/m2 for Overweight and >25 kg/m2 for obese as per WHO recommendation for Asian Indians, which is different for developed and developing countries. Role of gut microbiota mediated immune response in the development of obesity has been studied but the literature on Indian population are lacking. Therefore, a study was conducted to determine Toll like receptors (TLRs) in response to human gut microbiota of Indian obese and lean individuals using viable colonocytes in a Non invasive technique and Flowcytometry. Methods: A total of 20 healthy volunteer (10 obese and 10 lean) were enrolled in the study as per inclusion and exclusion criteria. Viable colonocytes were isolated from fecal samples using a Non invasive technique (SCSR Method). Toll like receptors (TLRs) and immunoglobulin (IgA &IgG) receptor concentration were measured by standard Flowcytometry methods using specific fluorochrome conjugated antibodies. Results: Average TLR2 receptor concentration was significantly higher in obese (6.35 %) as compared to lean (2.9 %) (P = 0.01). TLR4 receptor concentration was 1.4 % in obese and 1.65 % in lean although the difference was not statistically significant (P = 0.59). IgA & IgG receptor concentration was 49.6 % & 11.2 % in the obese and 67.15 % & 8.05 % in the lean respectively but the differences among both the group were not statistically significant. Conclusion: The results of the present study will be helpful for physicians and researchers to find some biomarkers which can determine predisposition of the obesity in Indian population and helps to use alternative therapeutics such as probiotics to maintain gut homeostasis and immune modulation to prevent obesity.
Background: We determined the magnitude and clinico-microbiological profile of prosthetic joint i... more Background: We determined the magnitude and clinico-microbiological profile of prosthetic joint infection (PJI) at a tertiary hospital. The diagnostic potential of 16S rRNA gene polymerase chain reaction (PCR) and sequencing on periprosthetic tissue samples was evaluated for the diagnosis of PJI. Materials and Methods: This ambispective cohort study consisted of patients who underwent primary or revision hip or knee arthroplasty from June 2013 to June 2017. The patients were classified as either infected or noninfected according to criteria set out by the musculoskeletal infection society (MSIS). Three to five periprosthetic tissue samples were collected from each patient for culture and 16S rRNA gene PCR sequencing. Results: Hundred and six patients were diagnosed to have PJI as per the MSIS Criteria. The cumulative incidence of PJI at our Institute at the end of 36 months was 1.1% (95% confidence interval [CI]: 0.59–2.91). Microorganisms were isolated by periprosthetic tissue culture (PTC) in 84 patients (sensitivity: 79% and specificity: 100%). Gram-negative aerobes were most frequently isolated (61%). Polymicrobial infections were present in 8.3% of cases. The most common infecting microorganism was Staphylococcus aureus (19.5%). Multidrug resistance and methicillin resistance were noted in 54% and 34% of bacterial isolates, respectively. The sensitivity and specificity of 16S rRNA PCR of periprosthetic tissue was 86% (95% CI: 74.9–89.9) and 100% (95% CI: 94.7–100), respectively. Periprosthetic tissue 16S rRNA PCR was more sensitive than PTC (P = 0.008), although both were 100% specific (P = 0.99). Conclusions: The incidence of PJI at our Institute compares well with other published reports. Contrary to previous reports, a predominance of Gram-negative PJI's was found. The preponderance of multidrug-resistant organisms in PJI's is worrisome. The high sensitivity and specificity of the 16S PCR assay used in our study support its use in culture-negative PJI suspected cases.
Mycoplasma pneumoniae is known to be a major cause of lower respiratory tract infections (LRTIs) ... more Mycoplasma pneumoniae is known to be a major cause of lower respiratory tract infections (LRTIs) in children. We studied 75 children who had been hospitalized for community-acquired LRTIs for the detection of M. pneumoniae by serological analysis and polymerase chain reaction (PCR) to amplify a 277-base pair region of 16S rDNA gene of M. pneumoniae applied to throat swab specimens. Serological and/or PCR positive results diagnosed M. pneumoniae infection in 23 (30.7%) patients.
The authors describe a case series of co-infection with COVID-19 and scrub typhus in two Indian p... more The authors describe a case series of co-infection with COVID-19 and scrub typhus in two Indian patients. Clinical features like fever, cough, dyspnea and altered sensorium were common in both patients. Case 1 had lymphopenia, elevated IL-6 and history of hypertension, while case 2 had leukocytosis and an increased liver enzymes. Both patients had hypoalbuminemia and required admission to the intensive care unit; one of them succumbed to acute respiratory distress syndrome further complicated by multiple organ dysfunction syndrome. Seasonal tropical infections in COVID-19 patients in endemic settings may lead to significant morbidity and mortality. Therefore, high clinical suspicion and an early diagnosis for co-infections among COVID-19 patients are essential for better patient management.
SARS-CoV-2 evolution has continued to generate variants, responsible for new pandemic waves local... more SARS-CoV-2 evolution has continued to generate variants, responsible for new pandemic waves locally and globally. Varying disease presentation and severity has been ascribed to inherent variant characteristics and vaccine immunity. This study analyzed genomic data from 305 whole genome sequences from SARS-CoV-2 patients before and through the third wave in India. Delta variant was responsible for disease in patients without comorbidity(97%), while Omicron BA.2 caused disease primarily in those with comorbidity(77%). Tissue adaptation studies brought forth higher propensity of Omicron variants to bronchial tissue than lung, contrary to observation in Delta variants from Delhi. Study of codon usage pattern distinguished the prevalent variants, clustering them separately, Omicron BA.2 isolated in February grouped away from December strains, and all BA.2 after December acquired a new mutation S959P in ORF1b (44.3% of BA.2 in the study) indicating ongoing evolution. Loss of critical spik...
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