Kiran Chawla

Pulmonary nocardiosis due to Nocardia otitidiscaviarum in an immunocompetent host- a rare case report

Nocardiosis is a localized or disseminated infection caused by soil-borne aerobic actinomycetes. Pulmonary nocardiosis is a rare infection mostly occurring in immunocompromised patients. We reported a case of 36 year old immunocompetent non-smoker female patient with no premorbid illness who presented with fever, cough with scanty sputum, hemoptysis, left sided chest pain and exertional dyspnea for two weeks. There was no past history of tuberculosis, diabetes mellitus or steroid therapy. Chest X-ray showed homogenous peripherally based opacity in the left upper zone. Bronchoscopy was done and brushing sent for culture, which showed colonies with features of Nocardia species after 48 hours. Further phenotypic characterization revealed it to be Nocardia otitidiscaviarum. Patient was treated with cotrimaxazole for six months after which complete recovery was evidenced symptomatically and radiologically. We report this case to emphasize the fact that among the Nocardia species, Nocardia otitidiscaviarum as causative agent of pulmonary disease is rarely reported even in immunocompromised individuals.

Genotypic detection of fluoroquinolone resistance in drug-resistant Mycobacterium tuberculosis at a tertiary care centre in south Coastal Karnataka, India

OBJECTIVES This study aimed to characterise mutations associated with fluoroquinolone resistance in drug-resistant Mycobacterium tuberculosis clinical isolates at a tertiary care centre in south Coastal Karnataka, India. METHODS DNA from 50 M. tuberculosis clinical isolates was extracted and the gyrA and gyrB genes were amplified. Purified amplicons of gyrA and gyrB were sequenced and extended-sequencing PCR products were analysed. Analysis of mutations in gyrA and gyrB was done using the MUBII-TB-DB database. Statistical analysis was performed using SPSS v.22 and data were compared by χ2 test. A P-value of <0.05 was considered statistically significant. RESULTS Mutations conferring resistance to fluoroquinolones were observed in 9 isolates (18%). The gyrA A281G (D94G) mutation was observed in 3 isolates (6%), whereas mutations G280T (D94Y) and A281C (D94A) were each observed in 1 isolate (2%). Mutation G1498A (D500N) in gyrB alone was observed in 2 isolates (4%). Two isolates (4%) had mutations both in gyrA and gyrB; gyrA mutation T271C (S91P) was observed in one isolate, whereas the other isolate had gyrA C269G (A90G), but both isolates had a common G1498A (D500N) gyrB mutation. G284C mutation conferring S95T polymorphism (not associated with fluoroquinolone resistance) was observed in 39/50 isolates (78%). CONCLUSION gyrA mutations at codons 94, 91 and 90 and gyrB mutation G1498A (D500N) were the most common mutations associated with fluoroquinolone resistance in clinical isolates in this study. Future studies including a larger number of samples are desirable to fully explore the true extent of fluoroquinolone resistance and mutations associated with them.

Strain diversity and relative transmission of Mycobacterium tuberculosis in south coastal Karnataka, India

BACKGROUND There are no published reports on the strain diversity and relative transmission of Mycobacterium tuberculosis isolates circulating in Karnataka State, India. OBJECTIVE To explore the strain diversity of M. tuberculosis isolates and their relative transmission in south coastal Karnataka using spoligotyping and mycobacterial interspersed repetitive unit-variable number of tandem repeats (MIRU-VNTR) typing. DESIGN A total of 108 clinical isolates of M. tuberculosis were processed for spoligotyping, and 12-locus MIRU-VNTR typing and cluster analysis was performed. RESULTS Spoligotyping data of 108 isolates revealed 63 spoligotype patterns: 36 (80 isolates, 74.1%) patterns corresponded to spoligotype international types (SITs), whereas 27 (28 isolates, 25.9%) patterns were orphans. A further 57 (52.8%) isolates were clustered into 12 clusters; 51 (47.2%) isolates were unique. The largest spoligotype cluster comprised SIT 48 (L1.2.2), followed by SIT 1942 (L3) and SIT 11 (L1.1.2). Combined MIRU-VNTR typing and spoligotyping analysis further differentiated these 108 isolates into five clusters of two isolates each and 98 individual patterns. CONCLUSIONS Combined use of spoligotyping and MIRU-VNTR typing is best suited for genotyping studies in this region. Very high genetic diversity was observed among the clinical isolates. Further elaborate studies are required for a better understanding of the genetic diversity and transmission dynamics of the strains circulating in this region.

Anaerobic bacteria in clinical specimens – Frequent, but a neglected lot: A five year experience at a tertiary care hospital

INTRODUCTION Anaerobic bacteria which constitute a significant proportion of the normal microbiota also cause variety of infections involving various anatomic sites. Considering the tedious culture techniques with longer turnaround time, anaerobic cultures are usually neglected by clinicians and microbiologists. AIM To study the frequency of isolation of different anaerobic bacteria from various clinical specimens. MATERIALS AND METHODS A retrospective study to analyse the frequency of isolation of different anaerobic bacteria, was conducted over a period of five years from 2011 to 2015 including various clinical specimens submitted to anaerobic division of Microbiology laboratory. Anaerobic bacteria were isolated and identified following standard bacteriological techniques. RESULTS Pathogenic anaerobes (n=336) were isolated from 278 (12.48%) of overall 2227 specimens processed with an average yield of 1.2 isolates. Anaerobes were isolated as polymicrobial flora with or without aerobic bacterial pathogens in 159 (57.2%) patients. Anaerobic Gram-negative bacilli (140, 41.7%) were the predominant isolates. B. fragilis group (67, 19.9%) were the most commonly isolated anaerobic pathogens. Anaerobes were predominantly isolated from deep seated abscess (23.9%). CONCLUSION Pathogenic anaerobes were isolated from various infection sites. Unless culture and susceptibility tests are performed as a routine, true magnitude of antimicrobial resistance among anaerobic pathogens will not be known. Knowledge of the distribution of these organisms may assist in the selection of appropriate empirical therapy for anaerobic infections.

Micro-Raman spectroscopy for identification and classification of UTI bacteria

Urinary tract infection (UTI) is one of the major clinical problems known to mankind, especially among adult women. Conventional methods for identification of UTI causing bacteria are time consuming and expensive. Therefore, a rapid and cost-effective method is desired. In the present study, five bacteria (one Gram-positive and four Gram-negative), most commonly known to cause UTI, have been identified and classified using micro-Raman spectroscopy combined with principal component analysis (PCA).

Rare Case of Polymicrobial Keratitis With Balantidium coli.

Purpose: To report a rare case of polymicrobial keratitis due to Balantidium coli and gram-negative bacteria, Pseudomonas aeruginosa and Klebsiella pneumoniae, in a soft contact lens (CL) wearer. Methods: We report a case of CL-related keratitis due to B. coli, P. aeruginosa, and K. pneumoniae. Results: The culture of the corneal scrapings, the CL cleaning solution, and the CL revealed the growth of a rare ciliated parasite, B. coli, along with gram-negative bacteria, namely, P. aeruginosa and K. pneumoniae. The patient was successfully treated with topical broad-spectrum antibiotics and intravenous metronidazole. Conclusions: Polymicrobial keratitis has seldom been reported with B. coli as the causative agent. CL wear can be a risk factor for this infection. Treatment with topical antibiotics may not suffice, and the intravenous route of antiprotozoal drugs may be a useful adjunct. Increasing awareness, early diagnosis, and treatment may improve the final visual outcome.