Shashidhar Vishwanath

Microbial quality of well water from rural and urban households in Karnataka, India: A cross-sectional study

OBJECTIVE The objective of this study was to evaluate the microbial quality of the well water used as a drinking source in urban and rural households. METHODS A total of 80 household well water samples were analyzed by the multiple fermentation tube method to determine the presumptive coliform count/most probable number of coliforms, and the isolates were identified using standard procedures, followed by susceptibility testing. RESULTS Fecal indicator organisms, including Escherichia coli and Enterococcus spp. were isolated from 22 (27.5%) samples, and the majority (92.5%) of the water sources were contaminated with coliforms. A total of 170 bacterial isolates were obtained, including coliforms (70%), Enterococcus spp. (1.8%) and saprophytes (28.2%). A significant number of isolates were multi-drug resistant, which is a cause of concern. A comparison of the microbial quality of the water between urban and rural households revealed no significant differences. CONCLUSION It might be prudent to monitor the bacteriological quality of well water at the source in addition to resistance profiles of the isolates.

Influence of Pseudomonas aeruginosa on exacerbation in patients with bronchiectasis

Background: A majority of the studies done on the western population have shown that Pseudomonas aeruginosa causes many severe infections in patients with bronchiectasis as compared to other pathogens. There is scarcity of similar data from the Asian population. Materials and Methods: A prospective study was undertaken to identify the various pathogens isolated from the respiratory samples of 117 patients with bronchiectasis from south India and to compare the clinicomicrobiological profile of infections caused by P. aeruginosa and other respiratory pathogens. Results: The respiratory pathogens were isolated from 63 (53.8%) patients. P. aeruginosa was the most common isolate (46.0%) followed by Klebsiella pneumoniae (14.3%) and other pathogenic bacteria. Patients included in the P. aeruginosa group had a higher number of exacerbations (p: 0.008), greater number of hospital admissions (p: 0.007), a prolonged hospital stay (p: 0.03), and poor lung function, compared to the patients infected with the non-Pseudomonas group. Conclusion: It is necessary to investigate the etiology of respiratory tract infections among bronchiectasis patients followed by the prompt management of cases diagnosed with P. aeruginosa infections, so as to lower the morbidity and have a better prognosis.

Prevalence of Clinical Periodontitis and Putative Periodontal Pathogens among South Indian Pregnant Women

In view of recent understanding of the association of periodontal infections and adverse pregnancy outcomes, the present investigation was undertaken to study the periodontal infections among 390 asymptomatic pregnant women and to find an association of bacterial etiologies with the disease. Prevalence of gingivitis was 38% and clinical periodontitis was 10% among the study population. Subgingival plaque specimens were subjected to multiplex PCR targeting ten putative periodontopathogenic bacteria. Among the periodontitis group, high detection rates of Porphyromonas gingivalis (56%), Prevotella nigrescens (44%), Treponema denticola (32%), and Prevotella intermedius (24%) were noted along with significant association with the disease (P < 0.05).

Acute post-traumatic endophthalmitis secondary to Propionibacterium acnes.

Propionibacterium acnes has rarely been reported as the causative organism in acute endophthalmitis following penetrating ocular trauma. We report a 53-year-old man, who presented with best corrected vision of counting fingers at 2 m, <N36, in the right eye and clinical features suggestive of endophthalmitis following penetrating trauma with a tree branch 2 days earlier. Conjunctival swab, aqueous and vitreous tap were sent for aerobic, anaerobic and fungal culture. The patient was treated with intravitreal ceftazidime, vancomycin along with topical antibiotics and steroids. An aqueous anaerobic culture was positive for P acnes. At the fifth month follow-up, the best corrected vision had improved to 20/20, N6. Thus, a good visual outcome was achieved, following appropriate treatment of a rather unusual causative organism.

Stenotrophomonas maltophilia in Lower Respiratory Tract Infections

BACKGROUND Stenotrophomonas maltophilia infection is gaining importance as an important cause of nosocomial pneumonia due to its characteristic inherent resistance to many broad- spectrum antibiotics. In this study we evaluated the demographic, clinical and microbiological profile of patients with lower respiratory tract infection due to Stenotrophomonas maltophilia. MATERIALS AND METHODS A retrospective analysis of 33 patients diagnosed with Stenotrophomonas maltophilia lower respiratory tract infections during a period of two years from 2012 - 2013 was done. RESULTS The predominant predisposing factor observed was mechanical ventilation in 17(51.5%) cases. Fluoroquinolones were the most effective antibiotic (26;78.8%) followed by trimethoprim-sulfamethoxazole (24;72.7%). Among the 19 patients treated with proper antibiotic, 13(68.4%) showed clinical improvement. Among the 14 patients who did not receive appropriate antibiotic for Stenotrophomonas maltophilia infection, 8(57.1%) showed improvement. Two (6%) had blood culture positive for Stenotrophomonas maltophilia. Mortality rate was 21.2%. CONCLUSION Stenotrophomonas maltophilia is emerging as an important nosocomial pathogen with increased risk in patients on mechanical ventilation in ICU. Empiric therapy should include agents active against S.maltophilia such as newer flouroquinolones and trimethoprim-sulfamethoxazole.

Nonfermenting Gram-negative Bacilli other than Pseudomonas aeruginosa and Acinetobacter Spp. Causing Respiratory Tract Infections in a Tertiary Care Center

Background: Nonfermenting gram-negative bacilli have emerged as important healthcare-associated pathogens. It is important to correctly identify all clinically significant nonfermenting gram-negative bacilli considering the intrinsic multidrug resistance exhibited by these bacteria. Materials and Methods: A retrospective study was undertaken to identify the various nonfermenting gram-negative bacilli other than Pseudomonas aeruginosa and Acinetobacter spp. isolated from respiratory samples (n = 9363), to understand their clinical relevance and to analyze their antibiotic susceptibility pattern. Results: Nonfermenting gram-negative bacilli were isolated from 830 (16.4%) samples showing significant growth. Thirty-three (4%) isolates constituted nonfermenting gram-negative bacilli other than P. aeruginosa and Acinetobacter spp. Stenotrophomonas maltophilia (15, 45.5%) was the most common isolate followed by Burkholderia cepacia (4, 12.1%), Sphingomonas paucimobilis (3, 9.1%), and Achromobacter xylosoxidans (3, 9.1%). On the basis of clinicomicrobiological correlation, pathogenicity was observed in 69.7% (n = 23) isolates. Timely and correct treatment resulted in clinical improvement in 87.9% cases. Conclusion: Any nonfermenting gram-negative bacilli isolated from respiratory tract infection should not be ignored as mere contaminant, but correlated clinically for its pathogenic potential and identified using standard methods so as to institute appropriate and timely antibiotic coverage.

Role of multiplex polymerase chain reaction in diagnosing tubercular meningitis

Tuberculous meningitis (TBM) is one of the most serious manifestations of extrapulmonary tuberculosis. Timely and accurate diagnosis provides a favorable prognosis in patients with TBM. The study evaluated the use of multiplex polymerase chain reaction (PCR) in the diagnosis of TBM. A study was conducted on 74 patients clinically suspected with TBM. The cerebrospinal fluid (CSF) specimens were processed for smear microscopy, middle brook 7H9 culture, and multiplex PCR using primers directed against IS6110 gene and 38 kD protein for detection of Mycobacterium tuberculosis. The results were analyzed to assess the role of multiplex PCR in the diagnosis of TBM. A total of 26 (35.1%) patients were diagnosed with TBM. Microscopy was negative in all while culture was positive in two cases only. Comparing with clinical diagnosis and CSF adenosine deaminase levels of ≥10 U/L, multiplex PCR showed sensitivity, specificity, positive predictive value, and negative predictive value of 71.4%, 89.6%, 83.3%, and 81.2%, respectively, in the diagnosis of TBM.

Methicillin‑resistant Staphylococcus Aureus Nasal Colonization in Human Immunodeficiency Virus‑infected Patients

Background: Staphylococcus aureus infections account for significant morbidity in human immunodeficiency virus (HIV)-infected individuals. Colonization by methicillin-resistant S. aureus (MRSA) usually precedes the development of subsequent infections. Aim: To study the frequency of MRSA colonization and to analyze its risk factors among HIV-infected adult patients. Materials and Methods: A prospective study was conducted including 194 HIV-infected patients. Anterior nasal swabs were obtained and processed for isolation of MRSA following standard guidelines. Risk factors for MRSA colonization were assessed, and the antimicrobial susceptibility profile of the MRSA isolates including low-level resistance to mupirocin was studied. Data were analyzed using SPSS statistical software. Results: MRSA colonization of anterior nares was found in 49 patients (25.3%). Patients put on antibiotics in the prior 3 months (P = 0.001) and those with percutaneous device in the past year (P = 0.001) were more likely to be MRSA colonized. Antiretroviral therapy was found to be protective against MRSA colonization (P = 0.004). Low-level mupirocin resistance was found in four (8.2%) isolates of MRSA. Conclusion: A significant proportion of HIV-infected patients were found to have MRSA colonization. Detection and monitoring for MRSA carriage status may be considered to reduce infections caused by MRSA in HIV-infected individuals.

Brain Abscess with Anaerobic Gram-Negative Bacilli: Case Series

Brain abscess is usually of polymicrobial etiology involving aerobic and obligate anaerobic bacteria. Anaerobic bacteria are mainly seen in brain abscesses secondary to otogenic and odontogenic source. Investigating for anaerobic etiology is usually neglected considering the tedious and time consuming process of anaerobic culture. It is necessary to perform anaerobic cultures along with routine aerobic cultures as a part of microbiological workup of abscess aspirates in patients with brain abscess which aid in providing appropriate antibiotic therapy. To highlight the significance of anaerobic cultures, we report four cases of brain abscess with anaerobic etiology from a tertiary care hospital in coastal Karnataka.

Point-of-Care Ultrasound for Extrapulmonary Tuberculosis in India: A Prospective Cohort Study in HIV-Positive and HIV-Negative Presumptive Tuberculosis Patients

Diagnosing extrapulmonary tuberculosis (EPTB) is challenging. Point-of-care ultrasound (POCUS) for human immunodeficiency virus (HIV)-associated EPTB is applied in sub-Saharan Africa. This study aimed at evaluating the applicability of POCUS for diagnosing EPTB in HIV-positive and HIV-negative presumptive tuberculosis (TB) patients in India, a country of moderate relative TB and HIV burden. Presumptive TB patients at Kasturba Hospital, Manipal, India, prospectively underwent POCUS evaluating for pericardial, pleural and ascitic effusion, abdominal lymphadenopathy, and hepatic and splenic microabscesses. Findings were correlated with TB category (confirmed TB, clinical TB, unlikely TB), HIV status, and discharge diagnoses. A total of 425 patients underwent POCUS; 81 (20%) were HIV-positive. POCUS findings were more common in HIV/TB coinfected patients than in HIV-positive patients with unlikely TB (24/40 (60%) versus 9/41 (22%), P < 0.001). Abdominal lymphadenopathy and splenic microabscesses were strongly associated with TB in HIV-positive patients (P = 0.002 and P = 0.001). POCUS findings did not correlate with TB in HIV-negative patients; a third of HIV-negative patients with unlikely TB and POCUS findings had cancer, another third other infectious diseases. Sonographic findings were common in HIV-positive and HIV-negative presumptive TB patients. POCUS was a useful bedside test for the detection of HIV-associated EPTB. In HIV-negative patients, POCUS detected features associated with EPTB but also of malignancy and other infectious diseases.