S Krishna Prakash

Salmonella senftenberg: a new pathogen in the burns ward

This is the first report of Salmonella senftenberg serovar outbreak in a burns unit. This unit admits about 2000 patients with major burn injuries annually. Routine sampling from wound swabs in December 1995 revealed S. senftenberg in a few samples following which a study was instituted from January to March 1996. Of 446 burn admissions during this period 80 patients were culture positive for S. senftenberg in wound swabs. The protocol for investigation included wound swabs on admission and then at biweekly interval, blood culture studies on clinically toxic patients, anti-microbial sensitivity studies, environmental sampling and hand swabs and stool cultures from about 50 staff members of the burns ward. No wound swab at the time of admission was positive for S. senftenberg. Environmental study and the study of staff members did not reveal any obvious source of the infection. S. senftenberg strains were sensitive to more than seven of the 11 anti-microbials tested at the beginning of the study but later 96.3% of the strains showed multidrug (more than three drugs) resistance. By April 1996 the isolates became negligible and later disappeared completely. The organism resurfaced again in March 1997 and the same study was instituted again on 413 admissions between March and May 1997. Fifty patients were culture positive for S. senftenberg. This time stool sample from one burn dresser tested positive for S. senftenberg. Interestingly, again at the beginning of the second outbreak the Salmonella strains were sensitive to 9 out of 11 anti-microbials tested, but later 96.11% strains became multidrug resistant. S. senftenberg strains showed maximum resistance to amoxycillin (97.5%) and minimum to chloramphenicol, tetracycline and cotrimoxazole (12%). It was noticed that Salmonella strains surfaced in wound swabs after 3-4 weeks of hospital stay. Forty-five out of 130 patients studied, in both the episodes, died due to septicemia. The majority of the patients who died had sustained > 60% TBSA burns. Blood cultures were done in 34/130 patients and eight yielded growth (2 S. senftenberg, 4 Klebsiella spp., and two Pseudomonas spp.)

Bacteriological profile of community-acquired pyodermas with special reference to methicillin resistant Staphylococcus aureus.

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Incidence and Risk Factors of Nasal Carriage of Staphylococcus aureus in HIV-Infected Individuals in Comparison to HIV-Uninfected Individuals A Case–Control Study

The study was conducted to evaluate the prevalence of nasal colonization of Staphylococcus aureus in individuals with HIV infection attending the Integrated Counselling and Testing Centre in a teaching hospital and compare the prevalence with HIV-uninfected individuals. A case–control study was conducted among newly diagnosed HIV-infected individuals and an equal number of age-group and sex-matched HIV-uninfected individuals, and nasal swabs were collected from both the samples. Sociodemographic and clinical data were collected through individual interviews. Ethical aspects were respected. A total of 100 individuals participated in the study, and 22 (44%) of the 50 HIV-infected cases were colonized by S aureus, including 19 (86.4%) methicillin-sensitive S aureus (MSSA) and 3 (13.6%) methicillin-resistant S aureus (MRSA). Only 12 (24%) strains were isolated from 50 HIV-uninfected individuals, with 11 being MSSA and 1 being MRSA. This difference in the isolation rate was statistically significant (P = .035). The 2 most commonly encountered risk factors in both the groups appeared to be history of tuberculosis and history of surgical procedures but none being statistically significant (P = .093 and P = .996). All the strains of S aureus were sensitive to mupirocin. The study concluded that HIV-infected individuals are at a higher risk of carriage as compared to HIV-uninfected individuals. By eliminating carriage in immunocompromised individuals, infections due to S aureus can also be minimized.

Pleuro pulmonary infection with Salmonella group E.

A patient was admitted with a history of cough, shortness of breath and fever. After investigations, he was found to have a left-sided pneumonia with pleural effusion. Culture of the patients sputum, pleural fluid and blood revealed Salmonella senftenberg. The patient was started on antibiotics according to the sensitivity report and responded to therapy. The past history revealed attempt at suicide by the intake of corrosive acid, which caused an esophageal stricture. The leak of gastric contents into the mediastinum lead to the infection of the pleural cavity and pneumonia.

Cell-mediated and humoral immunity in leprosy in children.

Cell‐mediated and humoral immunity were studied in 25 children between 0 and 14 years with leprosy. Cell‐mediated immunity was studied in vivo by lepromin and epicutaneous sensitization with dinitrochlorobenzene (DNCB) and T‐lymphocytes and their subpopulations (T4 and T8) in the peripheral blood. Humoral immunity was evaluated by B‐lymphocyte count and immunoglobulins (IgG, IgM and IgA). Along with complement, component C3 was also measured in the serum. Lepromin (Mitsuda) and DNCB responses were significantly poor in mid‐borderline (BB) leprosy. The hematological profile, including T‐lymphocytes, their subpopulations, B‐lymphocytes, serum immunoglobulins, and C3, were found to be normal in all forms of leprosy. The relatively short duration of disease and the low bacterial load may explain these findings.

Prevalence of community-acquired methicillin-resistant Staphylococcus aureus in patients with skin and soft tissue infections

Introduction: In the early nineties, infections due to methicillin-resistant Staphylococcus aureus (MRSA) in patients without previous healthcare exposure were reported. The continued evolution of MRSA is illustrated by the infections caused by community acquired MRSA and the majority of these infections are nonlife-threatening infections of the skin and soft tissues. We carried out the retrospective study of bacterial isolates obtained from pus specimens of community-acquired skin and soft tissue infections in our set up with special reference to MRSA. Materials and Methods: The isolation rate of various organisms isolated from pus specimens was recorded for the years 2007 to 2012. The antibiotic susceptibility patterns of S. aureus strains (MRSA and MSSA) were also reviewed. Results: 47.48% of the total pus samples received from patients with a clinical diagnosis of community acquired SSTI during the period of 6 years, that is, from 2007 to 2012, showed culture positivity. Mixed organisms were isolated from five samples. 30.21% of them were S. aureus strains out of which 23.80% demonstrated the presence of methicillin resistance (MRSA). All the MRSA strains (100%) screened from clinical specimens were resistant to penicillin, cephalexin and cefazolin; 40% to erythromycin, clindamycin and amikacin; 80% to gentamicin; 90% to ofloxacin. The isolation rate of MRSA is far outnumbered by that of MSSA that remains fairly sensitive to the first line drugs against S. aureus . Conclusion: Abscesses are the most common clinical presentation caused by CA-MRSA in this study and we recommend that physicians should consider obtaining cultures and antimicrobial susceptibility tests in all such patients.