Antibiotic Susceptibility Pattern Among CSOM Patients Attending AIMSR.

Background and Aim: CSOM causing deafness is seen in more than one third of the population in developing countries and is responsible for more than two thirds of deafness in children thereby causing intellectual and educational problems which have a profound impact on the society. Knowledge of the pathogens responsible for CSOM and their antibiotic sensitivity can assist in the selection of the appropriate treatment regimen in these cases. Objective: To identify the bacteria causing CSOM in our hospital area and to determine their antibiotic sensitivity. Methodology: Prospective study of 20 samples from clinically suspected cases of CSOM was performed over a period of two months. Samples were subjected to culture and the isolates were identified by standard biochemical tests. Antibiotic sensitivity testing was performed by modified Kirby-bauer disc diffusion technique as per CLSI guidelines. Results: The predominant organism isolated was Staphylococcus aureus. No other organism was isolated in our study. The antimicrobial sensitivity of the isolates in our study showed 100% sensitivity to ciprofloxacin,ofloxacin and netilmycin followed by 75% sensitivity to cefotaxime and ceftriaxone. Conclusion: The bacterial pathogens causing CSOM are unique to each geographical area. There is a high carriage of Staphylococcus aureus strains in the external auditory canal and upper respiratory tract prevalent in our hospital area. Quinolones and third generation cephalosporins are the most effective drugs for CSOM in our hospital area and can be considered for empiric therapy of these cases.

Linezolid resistant Staphylococcus aureus.

Linezolid is the only antibiotic available as an oral formulation for resistant staphylococcal infections. It is effective in skin & soft tissue infections, nosocomial pneumonias including VAP, infective endocarditis and MRSA meningitis. It is also effective in the eradication of both nasal & throat colonization of MRSA. Its high bioavailability and post antibiotic effect, ease of switching to oral therapy during its use and the fact that it can be used in patients of all ages, also in patients with liver disease and poor kidney function and its increased effectiveness over glycopeptides makes this drug a precious drug in the treatment of resistant staphylococcal infections. Linezolid resistance in staphylococcus is defined as a linezolid MIC of ≥8 mg/L. Reported Linezolid resistance in India and elsewhere is 2-20%. There is clonal dissemination of Linezolid Resistant Staphylococcus aureus (LRSA) within or across health care settings which demands continuous surveillance to determine the emergent risk of resistance strains and to establish guidelines for appropriate use. Clinical laboratories should confirm any LRSA preferably by a second method, prior to using linezolid for serious infections. Effective surveillance, more judicious use of this antibiotic, avoiding linezolid usage for empiric therapy in hospital acquired staphylococcus infections, optimization of the pharmacological parameters of the antibiotics in specific clinical situation, decreasing bacterial load by timely surgical debridement or drainage of collections, use of combination therapies would prevent the emergence of resistance to linezolid in staphylococcus aureus.

Cladophialophora bantiana.

Cladophialophora bantiana is one of the few neurotropic fungi which causes CNS infections in immunocompetant hosts. Cerebral phaeohyphomycosis caused by this fungus is one of the most difficult conditions to treat due to its poor prognosis and difficulty in management. Thermo-tolerance and multiple functions of melanin produced by this fungus is responsible for its role as pathogen in immunocompetent hosts. Early recognition and excision of lesion with antifungal therapy are required in the management of this condition. Culture and histopathology aid in the diagnosis. Research to find out a novel cost effective fungicidal agent against C. bantiana is the need of the day.

Role of enteropathogenic escherichia coli in paediatric diarrhoeas in South India.

Background: Enteropathogenic Escherichia coli( EPEC) is a major cause of diarrhoea in children below 5 years of age. Serotyping is the classical method and PCR detection of virulence factors is a rapid way of detecting diarrhoeagenic Esch.coli. Objectives : To study the role of EPEC in Paediatric diarrhoea by both Serogrouping and Multiplex PCR assay and to analyse the antibiotic susceptibililty pattern of EPEC strains in our area. Materials and Methods : Prospective study of stool samples collected from children with diarrhoea and without diarrhoea who were below 5 years of age was conducted from May to November 2011. EPEC isolates were identified by Serogrouping. Escherichia coli isolates were subjected to Serogrouping and Multiplex PCR assay and those isolates which showed pathogenic genes were further serotyped. Antibiotic susceptibility pattern of EPEC isolates was determined by Clinical and Laboratory Standards Institute guidelines. Results : Among the Escherichia coli isolates in the diarrhoeal group, 36.8% were identified as EPEC by Serogrouping and 38.8% of them were found to possess EAEC genes by molecular characterisation. In the nondiarrhoeal Esch. coli strains , none agglutinated with EPEC polyvalent sera, 46.6% showed EAEC genes out of which 85.7% were of a single serotype O153. Among the Escherichia coli isolates which agglutinated with EPEC polyvalent antisera , 33.3% were positive for Enteroaggregative genes. Conclusion : EPEC is still an important pathogen in paediatric diarrhoeas . O serogrouping can still be relied upon for detection of EPEC. EAEC are present in classical ‘ O ‘ serogroups. Serotype O 153 has an increasing potential for asymptomatic carrier state in children below 5 years of age.