Rapid, cost-effective, and sensitive diagnostic assays are essential for global tuberculosis (TB)... more Rapid, cost-effective, and sensitive diagnostic assays are essential for global tuberculosis (TB) control, especially in high TB burden, resource-limited settings. The current study was designed to evaluate diagnostic accuracy of Truenat MTB-Rif Dx (MolBio) in children less than 18 years of age, with symptoms suggestive of TB. Gastric aspirate, induced sputum, and broncho-alveolar lavage samples were subjected simultaneously to AFB-smear, GeneXpert MTB/RIF, liquid culture (MGIT-960) and Truenat MTB-Rif Dx. The index-test results were evaluated against microbiological reference standards (MRS). Truenat MTB-Rif Dx had a sensitivity of 57.1%, specificity of 92% against MRS. The sensitivity and specificity of the Truenat MTB-RIF Dx compared with liquid culture was 58.7% and 87.5% while GeneXpert MTB/RIF was 56% and 91.4%. The performance of both GeneXpert MTB/RIF and Truenat MTB-Rif Dx are comparable. Result of our study demonstrates that Truenat MTB-Rif can aid in early and efficient d...
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: The objective of this study is to investigate gonococcal isolates using phenotypic an... more BACKGROUND: The objective of this study is to investigate gonococcal isolates using phenotypic and genotypic methods. METHODOLOGY: Sixty gonococcal isolates obtained were examined. Strains were divided into 9 resistant phenotypes: Chromosomally mediated penicillin-resistant Neisseria gonorrhoeae (CMRNGP), penicillinase-producing NG (PPNG), chromosomally mediated tetracycline-resistant NG (CMRNGT), TRNG, PPNG and TRNG, CMRNGPT, quinolone resistant NG (QRNG), Azithro R, and decreased susceptibility (DS) to ceftriaxone. These isolates were also subjected to auxotyping and NG-multi-antigen sequence typing (MAST). RESULTS: Of 60 isolates, 32 (53.33%) PPNG and only one was CMRNGP; 16 (26.66%) were CMRNGT, while 18 (30%) were TRNG. Both PPNG and TRNG found in 13 (21.66%) and none were CMRNGPT. QRNG was seen in 93.33%, 5% Azithromycin R, and 6.66% were DS to ceftriaxone. Based on auxotyping, 24 (40%) nonrequiring, 16 (26.66%) were proline requiring, 13 (21.66%) arginine requiring while 7 (1...
Antimicrobial resistance in Neisseria gonorrhoeae, the causative agent of gonorrhoea, is a subjec... more Antimicrobial resistance in Neisseria gonorrhoeae, the causative agent of gonorrhoea, is a subject of worldwide attention. The present study was undertaken to examine the rates of ciprofloxacin resistance, to correlate mutations in gyrA and parC genes with the level of resistance and to look for a variation in mutation pattern, if any, in isolates from across the country. A total of 113 isolates of N. gonorrhoeae collected from sexually transmitted infection patients in six centres during November 2010 to October 2013 were investigated. Minimum inhibitory concentration (MIC) determination was done by E-test and results interpreted as per Calibrated Dichotomous Sensitivity criteria. DNA sequence analysis of gyrA and parC genes was done. Of the 113 isolates, only three (2.6%) were susceptible whereas eight (7.07%) were less susceptible, 32 [28.3%, 95% confidence interval (CI): 20.4-37.6%] resistant (MIC 1-3 μg/ml) and 70 (61.9%, 95% CI: 52.2-70.7%) exhibited high-level resistance (HLR...
clinic visitors. In view of the extensive resistance against doxycyclin and ciprofloxacin, these ... more clinic visitors. In view of the extensive resistance against doxycyclin and ciprofloxacin, these antibiotics are not appropriate treatment options for gonorrhoea; instead, extended spectrum cephalosporins are advised. Disclosure of interest statement The study is funded by Indonesian government through Beasiswa Unggulan (The Excellence
Systems Biology and Novel Technologies For Molecular Analysis and Diagnosis, 2017
By using PCR as gold standard VIA sensibility was 16.12% and the specificity 95.45%. Conclusion H... more By using PCR as gold standard VIA sensibility was 16.12% and the specificity 95.45%. Conclusion HPV circulate in Cote d'Ivoire in women attending for cervical cancer screnning by visual inspection with acetic acid or lugol. Visual inspection with acetic acid or lugol seem to have a good specificity. HPV Genotypes 16 and 18 included in the vaccine available seem to be the most prevalent.
Molecular epidemiology of 100 consecutive gonococcal isolates collected between April 2010 and Oc... more Molecular epidemiology of 100 consecutive gonococcal isolates collected between April 2010 and October 2013 from New Delhi was investigated using Neisseria gonorrhoeae multiantigen sequence typing (NG-MAST) along with its association with antimicrobial resistance profiles. Neisseria gonorrhoeae isolates were assigned into 60 different sequence types and 43 (71.6%) were novel. Sole representation was seen in 76.6% sequence types. There was significant association between ST6058 and resistance to penicillin (P = 0.00) and tetracycline (P = 0.002).
Indian journal of dermatology, venereology and leprology
The pathogenesis is unknown though Torrelo et al. suggested that vaccines may induce an immune re... more The pathogenesis is unknown though Torrelo et al. suggested that vaccines may induce an immune response against specific and non-specific antigens in patients with trigger factors and that the trauma of injection may cause endothelial damage and tissue hypoxia. [1] Different treatments have been tried including potent topical corticosteroids, systemic corticosteroids and methotrexate but none has proved effective. [1] Even though no case of progression to generalized morphea or of the development of systemic symptoms has been reported, we consider it important to follow-up the patient in order to assess the symmetric growth of the limbs and detect any appearance of systemic symptoms. [4]
Poster presentations the two proportions was highly significant. We also compared BV present in L... more Poster presentations the two proportions was highly significant. We also compared BV present in LSIL group with HSIL group. BV was present in 29% cases in LSIL group compared to 45% in HSIL group (P = 0.03). The difference between the two proportions was significant. Conclusion The presence of BV was significantly higher in SIL group and was associated with the severity of SIL. The presence of BV should not deter a diagnosis of SIL but trigger a meticulous search for abnormal cells. Giant Condyloma aCuminata of BusChke and lowenstein treated suCCessfully surGiCally
Indian Journal of Dermatology, Venereology, and Leprology, 2012
Background: Chlamydia trachomatis is the most common bacterial etiology of sexually transmitted i... more Background: Chlamydia trachomatis is the most common bacterial etiology of sexually transmitted infection. Aim: A pilot study was designed using PCR for amplification and detection of a specific 517 bp sequence of the common endogenous plasmid of C. trachomatis from clinical swab specimens obtained from symptomatic female patients attending STD clinics of AIIMS and Regional STD Teaching, Training & Research Center, Safdarjang Hospital, New Delhi. Methods: 97 patients were recruited in the study, and endocervical swabs were collected following standard procedures. The samples were analyzed by PCR and direct fluorescence antibody (DFA) for detection of C. trachomatis, and the sensitivity, specificity, PPV and NPV of PCR were calculated taking DFA as gold standard. Results: Out of 97 samples tested, 9 were positive for C. trachomatis by PCR. 1 PCR positive patient was negative by DFA although a total of 11 patients were positive by DFA. The sensitivity, specificity, PPV and NPV of PCR with reference to DFA was 72.73%, 98.84%, 88.89% and 96.59%, respectively. This PCR had high specificity and NPV for detection of C.trachomatis. Conclusions: In light of the introduction of enhanced syndromic approach, which involves the use of laboratory techniques (wherever possible) to confirm clinical diagnosis, a diagnostic PCR with high specificity and NPV is particularly valuable for determination of etiological diagnosis and hence contribute to judicious use of antimicrobials in the community.
Diagnostic Microbiology and Infectious Disease, 2021
Data on genetic characteristics of Neisseria gonorrhoeae isolates exhibiting decreased susceptibi... more Data on genetic characteristics of Neisseria gonorrhoeae isolates exhibiting decreased susceptibility to extended-spectrum cephalosporins in India is deficient. In this study, we have sequenced penA, porB, mtrR and ponA and blaTEM genes in 70 clinical isolates of NG with varying ceftriaxone MICs. Amongst these, 22 (31.4%) were PPNG. Additionally, N. gonorrheae Multiantigen Sequence Typing was performed. Fisher exact and χ2 were used to evaluate significance of mutations with MICs. A total of six non-mosaic penA (Penicillin binding protein 2 [PBP2]) amino acid patterns were seen (II, IV, IX, XII, XIX, XXII) of which, pattern IX was significantly associated with decreased susceptibility to ceftriaxone. Other significant associations were noted in porB & mtrR genes. There were no mutations in blaTEM gene. ST6069 was significantly associated with decreased susceptibility to ceftriaxone. To conclude, development of decreased susceptibility to ceftriaxone in gonococci involves cumulation of different mutations in the four chromosomal genes investigated.
The switch from conventional to molecular methods for the laboratory diagnosis of gonorrhoea is i... more The switch from conventional to molecular methods for the laboratory diagnosis of gonorrhoea is inspired by difficulties associated with cultivation coupled with constraints with regard to its sensitivity. In an endeavour to keep pace, we have developed an in-house polymerase chain reaction (PCR) targeting the opa gene of Neisseria gonorrhoeae using self-designed primers (GenBank accession no. for primers: PUID 9716120 SNUM 2706 Ng_opa). The sensitivity, specificity, positive predictive value and negative predictive value for this assay were found to be 100% (95% confidence interval [CI] 92.5–100), 97.9% (95% CI 95.6–99.1), 89.5% (95% CI 79.1–95.3) and 100% (95% CI 98.6–100), respectively.[1] We have been using this as the supplemental assay in conjunction with 16S ribosomal PCR for the detection of N. gonorrhoeae in urogenital samples. This is in compliance with 2002 CDC guidelines that prescribe routine repeat testing of all positive specimens. Recent CDC guidelines (2014) recommend retesting a positive genital tract specimen with an alternate target assay, primarily when nucleic acid amplification test used detects non-gonococcal Neisseria species.[2] In light of this advisory, we wanted to further assess the specificity of our assay. Although a few strains of non-Neisseria N. gonorrhoeae sp. were included during standardisation studies,[1] we went a step further to check the specificity of our PCR against a large panel of well-characterised commensal Neisseria sp. These included Neisseria cinerea, Neisseria flavescens, Neisseria lactamica, Neisseria mucosa, Neisseria subflava, Neisseria polysaccharea and Neisseria sicca. In addition, a phenotypically similar organism, Moraxella catarrhalis, which inhabits the upper respiratory tract, was included in the present investigation. Figure 1 shows that our primers detected only gonococcal Figure 1: Polymerase chain reaction results of opa gene. Lane 1: Blank, Lane 2: Control WHO F, Lane 3: 100 bp ladder, Lane 4: Neisseria gonorrhoeae ATCC 49226, Lane 5: Neisseria cinerea THO 148D10, Lane 6: Neisseria sicca ATCC 29193, Lane 7: Neisseria flavescens WARB 148D7, Lane 8: Neisseria lactamica KIRK 148E4, Lane 9: Neisseria sicca 1316 148E5, Lane 10: Neisseria mucosa BLEA 148E6, Lane 11: Neisseria subflava ELFO 148E10, Lane 12: Neisseria polysaccharea 33125 100F10, Lane 13: Moraxella catarrhalis NCTC11020 200J3, Lane 14: Neisseria sicca (clinical isolate), Lane 15: Neisseria sicca (clinical isolate), Lane 16: Neisseria sicca (clinical isolate) *S Mohanty, R Gaind
ABSTRACT Introduction The diagnosis of child abuse is based on a combination of child’s history, ... more ABSTRACT Introduction The diagnosis of child abuse is based on a combination of child’s history, physical findings, and when appropriate, laboratory and other tests. Overall, the diagnosis is often complicated but suspicion should always be followed by further investigations. Formulating a conclusion and reaching a diagnosis of child abuse may require the assistance and coming together of different specialities in the hospital. Case history: A seven year old girl presented to the Dermatology and Venereology OPD of a tertiary hospital in New Delhi, India with chief complaints of vaginal discharge for last 4 years. The vaginal swab(s) on Gram stain revealed numerous pus cells with GNDC, intracellular as well as extracellular. The child was treated based on clinical suspicion of gonorrhoea. However, RCUT put up from suspected colonies on modified Thayer Martin medium was positive for Neisseria meningitidis. In addition, crgA gene PCR from DNA extracted from the swab as well as the isolate was positive for N. meningitidis while opa-gene PCR for N. gonorrhoeae was negative. Although she was initially treated for suspected gonococcal infection, the clinical diagnosis was refuted by the results of culture and PCR. Discussion & conclusion: The findings of the present case emphasise the importance of careful culture techniques for isolation of organisms & their correct identification which is the cornerstone of appropriate therapy. It also drives home the necessity of using lactose in Rapid Carbohydrate Utilization Test (RCUT), which is crucial to differentiate between N. meningitidis and N. lactamica. It is also important for the laboratory (especially one that is considered a referral laboratory) to have capacity to perform molecular tests to confirm or refute presumptive findings, as was done in the present case. This observation stresses that an interdisciplinary approach appears to be a valuable tool for evaluating such children.
Indian Journal of Dermatology, Venereology, and Leprology, 2012
Chlamydia trachomatis is the most common bacterial etiology of sexually transmitted infection. A ... more Chlamydia trachomatis is the most common bacterial etiology of sexually transmitted infection. A pilot study was designed using PCR for amplification and detection of a specific 517 bp sequence of the common endogenous plasmid of C. trachomatis from clinical swab specimens obtained from symptomatic female patients attending STD clinics of AIIMS and Regional STD Teaching, Training & Research Center, Safdarjang Hospital, New Delhi. 97 patients were recruited in the study, and endocervical swabs were collected following standard procedures. The samples were analyzed by PCR and direct fluorescence antibody (DFA) for detection of C. trachomatis, and the sensitivity, specificity, PPV and NPV of PCR were calculated taking DFA as gold standard. Out of 97 samples tested, 9 were positive for C. trachomatis by PCR. 1 PCR positive patient was negative by DFA although a total of 11 patients were positive by DFA. The sensitivity, specificity, PPV and NPV of PCR with reference to DFA was 72.73%, 98.84%, 88.89% and 96.59%, respectively. This PCR had high specificity and NPV for detection of C.trachomatis. In light of the introduction of enhanced syndromic approach, which involves the use of laboratory techniques (wherever possible) to confirm clinical diagnosis, a diagnostic PCR with high specificity and NPV is particularly valuable for determination of etiological diagnosis and hence contribute to judicious use of antimicrobials in the community.
Rapid, cost-effective, and sensitive diagnostic assays are essential for global tuberculosis (TB)... more Rapid, cost-effective, and sensitive diagnostic assays are essential for global tuberculosis (TB) control, especially in high TB burden, resource-limited settings. The current study was designed to evaluate diagnostic accuracy of Truenat MTB-Rif Dx (MolBio) in children less than 18 years of age, with symptoms suggestive of TB. Gastric aspirate, induced sputum, and broncho-alveolar lavage samples were subjected simultaneously to AFB-smear, GeneXpert MTB/RIF, liquid culture (MGIT-960) and Truenat MTB-Rif Dx. The index-test results were evaluated against microbiological reference standards (MRS). Truenat MTB-Rif Dx had a sensitivity of 57.1%, specificity of 92% against MRS. The sensitivity and specificity of the Truenat MTB-RIF Dx compared with liquid culture was 58.7% and 87.5% while GeneXpert MTB/RIF was 56% and 91.4%. The performance of both GeneXpert MTB/RIF and Truenat MTB-Rif Dx are comparable. Result of our study demonstrates that Truenat MTB-Rif can aid in early and efficient d...
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: The objective of this study is to investigate gonococcal isolates using phenotypic an... more BACKGROUND: The objective of this study is to investigate gonococcal isolates using phenotypic and genotypic methods. METHODOLOGY: Sixty gonococcal isolates obtained were examined. Strains were divided into 9 resistant phenotypes: Chromosomally mediated penicillin-resistant Neisseria gonorrhoeae (CMRNGP), penicillinase-producing NG (PPNG), chromosomally mediated tetracycline-resistant NG (CMRNGT), TRNG, PPNG and TRNG, CMRNGPT, quinolone resistant NG (QRNG), Azithro R, and decreased susceptibility (DS) to ceftriaxone. These isolates were also subjected to auxotyping and NG-multi-antigen sequence typing (MAST). RESULTS: Of 60 isolates, 32 (53.33%) PPNG and only one was CMRNGP; 16 (26.66%) were CMRNGT, while 18 (30%) were TRNG. Both PPNG and TRNG found in 13 (21.66%) and none were CMRNGPT. QRNG was seen in 93.33%, 5% Azithromycin R, and 6.66% were DS to ceftriaxone. Based on auxotyping, 24 (40%) nonrequiring, 16 (26.66%) were proline requiring, 13 (21.66%) arginine requiring while 7 (1...
Antimicrobial resistance in Neisseria gonorrhoeae, the causative agent of gonorrhoea, is a subjec... more Antimicrobial resistance in Neisseria gonorrhoeae, the causative agent of gonorrhoea, is a subject of worldwide attention. The present study was undertaken to examine the rates of ciprofloxacin resistance, to correlate mutations in gyrA and parC genes with the level of resistance and to look for a variation in mutation pattern, if any, in isolates from across the country. A total of 113 isolates of N. gonorrhoeae collected from sexually transmitted infection patients in six centres during November 2010 to October 2013 were investigated. Minimum inhibitory concentration (MIC) determination was done by E-test and results interpreted as per Calibrated Dichotomous Sensitivity criteria. DNA sequence analysis of gyrA and parC genes was done. Of the 113 isolates, only three (2.6%) were susceptible whereas eight (7.07%) were less susceptible, 32 [28.3%, 95% confidence interval (CI): 20.4-37.6%] resistant (MIC 1-3 μg/ml) and 70 (61.9%, 95% CI: 52.2-70.7%) exhibited high-level resistance (HLR...
clinic visitors. In view of the extensive resistance against doxycyclin and ciprofloxacin, these ... more clinic visitors. In view of the extensive resistance against doxycyclin and ciprofloxacin, these antibiotics are not appropriate treatment options for gonorrhoea; instead, extended spectrum cephalosporins are advised. Disclosure of interest statement The study is funded by Indonesian government through Beasiswa Unggulan (The Excellence
Systems Biology and Novel Technologies For Molecular Analysis and Diagnosis, 2017
By using PCR as gold standard VIA sensibility was 16.12% and the specificity 95.45%. Conclusion H... more By using PCR as gold standard VIA sensibility was 16.12% and the specificity 95.45%. Conclusion HPV circulate in Cote d'Ivoire in women attending for cervical cancer screnning by visual inspection with acetic acid or lugol. Visual inspection with acetic acid or lugol seem to have a good specificity. HPV Genotypes 16 and 18 included in the vaccine available seem to be the most prevalent.
Molecular epidemiology of 100 consecutive gonococcal isolates collected between April 2010 and Oc... more Molecular epidemiology of 100 consecutive gonococcal isolates collected between April 2010 and October 2013 from New Delhi was investigated using Neisseria gonorrhoeae multiantigen sequence typing (NG-MAST) along with its association with antimicrobial resistance profiles. Neisseria gonorrhoeae isolates were assigned into 60 different sequence types and 43 (71.6%) were novel. Sole representation was seen in 76.6% sequence types. There was significant association between ST6058 and resistance to penicillin (P = 0.00) and tetracycline (P = 0.002).
Indian journal of dermatology, venereology and leprology
The pathogenesis is unknown though Torrelo et al. suggested that vaccines may induce an immune re... more The pathogenesis is unknown though Torrelo et al. suggested that vaccines may induce an immune response against specific and non-specific antigens in patients with trigger factors and that the trauma of injection may cause endothelial damage and tissue hypoxia. [1] Different treatments have been tried including potent topical corticosteroids, systemic corticosteroids and methotrexate but none has proved effective. [1] Even though no case of progression to generalized morphea or of the development of systemic symptoms has been reported, we consider it important to follow-up the patient in order to assess the symmetric growth of the limbs and detect any appearance of systemic symptoms. [4]
Poster presentations the two proportions was highly significant. We also compared BV present in L... more Poster presentations the two proportions was highly significant. We also compared BV present in LSIL group with HSIL group. BV was present in 29% cases in LSIL group compared to 45% in HSIL group (P = 0.03). The difference between the two proportions was significant. Conclusion The presence of BV was significantly higher in SIL group and was associated with the severity of SIL. The presence of BV should not deter a diagnosis of SIL but trigger a meticulous search for abnormal cells. Giant Condyloma aCuminata of BusChke and lowenstein treated suCCessfully surGiCally
Indian Journal of Dermatology, Venereology, and Leprology, 2012
Background: Chlamydia trachomatis is the most common bacterial etiology of sexually transmitted i... more Background: Chlamydia trachomatis is the most common bacterial etiology of sexually transmitted infection. Aim: A pilot study was designed using PCR for amplification and detection of a specific 517 bp sequence of the common endogenous plasmid of C. trachomatis from clinical swab specimens obtained from symptomatic female patients attending STD clinics of AIIMS and Regional STD Teaching, Training & Research Center, Safdarjang Hospital, New Delhi. Methods: 97 patients were recruited in the study, and endocervical swabs were collected following standard procedures. The samples were analyzed by PCR and direct fluorescence antibody (DFA) for detection of C. trachomatis, and the sensitivity, specificity, PPV and NPV of PCR were calculated taking DFA as gold standard. Results: Out of 97 samples tested, 9 were positive for C. trachomatis by PCR. 1 PCR positive patient was negative by DFA although a total of 11 patients were positive by DFA. The sensitivity, specificity, PPV and NPV of PCR with reference to DFA was 72.73%, 98.84%, 88.89% and 96.59%, respectively. This PCR had high specificity and NPV for detection of C.trachomatis. Conclusions: In light of the introduction of enhanced syndromic approach, which involves the use of laboratory techniques (wherever possible) to confirm clinical diagnosis, a diagnostic PCR with high specificity and NPV is particularly valuable for determination of etiological diagnosis and hence contribute to judicious use of antimicrobials in the community.
Diagnostic Microbiology and Infectious Disease, 2021
Data on genetic characteristics of Neisseria gonorrhoeae isolates exhibiting decreased susceptibi... more Data on genetic characteristics of Neisseria gonorrhoeae isolates exhibiting decreased susceptibility to extended-spectrum cephalosporins in India is deficient. In this study, we have sequenced penA, porB, mtrR and ponA and blaTEM genes in 70 clinical isolates of NG with varying ceftriaxone MICs. Amongst these, 22 (31.4%) were PPNG. Additionally, N. gonorrheae Multiantigen Sequence Typing was performed. Fisher exact and χ2 were used to evaluate significance of mutations with MICs. A total of six non-mosaic penA (Penicillin binding protein 2 [PBP2]) amino acid patterns were seen (II, IV, IX, XII, XIX, XXII) of which, pattern IX was significantly associated with decreased susceptibility to ceftriaxone. Other significant associations were noted in porB & mtrR genes. There were no mutations in blaTEM gene. ST6069 was significantly associated with decreased susceptibility to ceftriaxone. To conclude, development of decreased susceptibility to ceftriaxone in gonococci involves cumulation of different mutations in the four chromosomal genes investigated.
The switch from conventional to molecular methods for the laboratory diagnosis of gonorrhoea is i... more The switch from conventional to molecular methods for the laboratory diagnosis of gonorrhoea is inspired by difficulties associated with cultivation coupled with constraints with regard to its sensitivity. In an endeavour to keep pace, we have developed an in-house polymerase chain reaction (PCR) targeting the opa gene of Neisseria gonorrhoeae using self-designed primers (GenBank accession no. for primers: PUID 9716120 SNUM 2706 Ng_opa). The sensitivity, specificity, positive predictive value and negative predictive value for this assay were found to be 100% (95% confidence interval [CI] 92.5–100), 97.9% (95% CI 95.6–99.1), 89.5% (95% CI 79.1–95.3) and 100% (95% CI 98.6–100), respectively.[1] We have been using this as the supplemental assay in conjunction with 16S ribosomal PCR for the detection of N. gonorrhoeae in urogenital samples. This is in compliance with 2002 CDC guidelines that prescribe routine repeat testing of all positive specimens. Recent CDC guidelines (2014) recommend retesting a positive genital tract specimen with an alternate target assay, primarily when nucleic acid amplification test used detects non-gonococcal Neisseria species.[2] In light of this advisory, we wanted to further assess the specificity of our assay. Although a few strains of non-Neisseria N. gonorrhoeae sp. were included during standardisation studies,[1] we went a step further to check the specificity of our PCR against a large panel of well-characterised commensal Neisseria sp. These included Neisseria cinerea, Neisseria flavescens, Neisseria lactamica, Neisseria mucosa, Neisseria subflava, Neisseria polysaccharea and Neisseria sicca. In addition, a phenotypically similar organism, Moraxella catarrhalis, which inhabits the upper respiratory tract, was included in the present investigation. Figure 1 shows that our primers detected only gonococcal Figure 1: Polymerase chain reaction results of opa gene. Lane 1: Blank, Lane 2: Control WHO F, Lane 3: 100 bp ladder, Lane 4: Neisseria gonorrhoeae ATCC 49226, Lane 5: Neisseria cinerea THO 148D10, Lane 6: Neisseria sicca ATCC 29193, Lane 7: Neisseria flavescens WARB 148D7, Lane 8: Neisseria lactamica KIRK 148E4, Lane 9: Neisseria sicca 1316 148E5, Lane 10: Neisseria mucosa BLEA 148E6, Lane 11: Neisseria subflava ELFO 148E10, Lane 12: Neisseria polysaccharea 33125 100F10, Lane 13: Moraxella catarrhalis NCTC11020 200J3, Lane 14: Neisseria sicca (clinical isolate), Lane 15: Neisseria sicca (clinical isolate), Lane 16: Neisseria sicca (clinical isolate) *S Mohanty, R Gaind
ABSTRACT Introduction The diagnosis of child abuse is based on a combination of child’s history, ... more ABSTRACT Introduction The diagnosis of child abuse is based on a combination of child’s history, physical findings, and when appropriate, laboratory and other tests. Overall, the diagnosis is often complicated but suspicion should always be followed by further investigations. Formulating a conclusion and reaching a diagnosis of child abuse may require the assistance and coming together of different specialities in the hospital. Case history: A seven year old girl presented to the Dermatology and Venereology OPD of a tertiary hospital in New Delhi, India with chief complaints of vaginal discharge for last 4 years. The vaginal swab(s) on Gram stain revealed numerous pus cells with GNDC, intracellular as well as extracellular. The child was treated based on clinical suspicion of gonorrhoea. However, RCUT put up from suspected colonies on modified Thayer Martin medium was positive for Neisseria meningitidis. In addition, crgA gene PCR from DNA extracted from the swab as well as the isolate was positive for N. meningitidis while opa-gene PCR for N. gonorrhoeae was negative. Although she was initially treated for suspected gonococcal infection, the clinical diagnosis was refuted by the results of culture and PCR. Discussion & conclusion: The findings of the present case emphasise the importance of careful culture techniques for isolation of organisms & their correct identification which is the cornerstone of appropriate therapy. It also drives home the necessity of using lactose in Rapid Carbohydrate Utilization Test (RCUT), which is crucial to differentiate between N. meningitidis and N. lactamica. It is also important for the laboratory (especially one that is considered a referral laboratory) to have capacity to perform molecular tests to confirm or refute presumptive findings, as was done in the present case. This observation stresses that an interdisciplinary approach appears to be a valuable tool for evaluating such children.
Indian Journal of Dermatology, Venereology, and Leprology, 2012
Chlamydia trachomatis is the most common bacterial etiology of sexually transmitted infection. A ... more Chlamydia trachomatis is the most common bacterial etiology of sexually transmitted infection. A pilot study was designed using PCR for amplification and detection of a specific 517 bp sequence of the common endogenous plasmid of C. trachomatis from clinical swab specimens obtained from symptomatic female patients attending STD clinics of AIIMS and Regional STD Teaching, Training & Research Center, Safdarjang Hospital, New Delhi. 97 patients were recruited in the study, and endocervical swabs were collected following standard procedures. The samples were analyzed by PCR and direct fluorescence antibody (DFA) for detection of C. trachomatis, and the sensitivity, specificity, PPV and NPV of PCR were calculated taking DFA as gold standard. Out of 97 samples tested, 9 were positive for C. trachomatis by PCR. 1 PCR positive patient was negative by DFA although a total of 11 patients were positive by DFA. The sensitivity, specificity, PPV and NPV of PCR with reference to DFA was 72.73%, 98.84%, 88.89% and 96.59%, respectively. This PCR had high specificity and NPV for detection of C.trachomatis. In light of the introduction of enhanced syndromic approach, which involves the use of laboratory techniques (wherever possible) to confirm clinical diagnosis, a diagnostic PCR with high specificity and NPV is particularly valuable for determination of etiological diagnosis and hence contribute to judicious use of antimicrobials in the community.
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Papers by Neeraj Mahajan