Chronic suppurative otitis media: a clinico-microbiological menace.

Background: Chronic Suppurative Otitis Media (CSOM) is an important cause of preventable hearing loss. Global emergence of resistant strains is of great concern. The aim of the present study was to determine the etiology and antibiotic sensitivity pattern of bacterial isolates from CSOM cases with special emphasis on ESBL (Extended Spectrum Beta- Lactamases) and AmpC beta lactamases. Methods: Patients with sign and symptoms suggestive of CSOM, ESBL (Extended Spectrum Beta-Lactamases), AmpC beta lactamases and MBLs (Metallo beta lactamases) were included. Two ear swabs were taken from all the patients and cultured on blood agar and MacConkey agar. Bacterial identification of isolates was done using standard biochemicals. Antimicrobial susceptibility was performed by Kirby-Bauer's disc diffusion method as per the Clinical Laboratory Standards Institute (CLSI) guidelines using antibiotic discs (HI MEDIA). Results: Out of 130 patients, 110(84.62%) had bacterial growth. The common pathogenic species were Pseudomonas aeruginosa 36(37.89%), Staphylococcus aureus 31(32.63%), Citrobacter koseri 9(9.47%) and Proteus vulgaris 6(6.32%). P. aeruginosa showed maximum sensitivity to colistin (94.4%), polymixin-B (91.3%) and imipenem (91.3%). Gram positive cocci showed maximum sensitivity to vancomycin (99%). MRSA (Methicillin Resistant Staphylococcus aureus) and HLAR (High Level Aminoglycoside Resistance) were detected in 9(29%) S. aureus and 1(50%) Enterococcus faecalis respectively. ESBL and AmpC were detected in 11(18.3%) and 12(20%) Gram negative bacteria, respectively and MBL producer was not detected. Conclusion: P. aeruginosa was found to be the most common isolate in CSOM cases and colistin, polymixin-B and imipenem was found to be most effective antibiotics.

Prevalence of genotype D in chronic liver disease patients with occult HBV infection in northern region of India.

Background: Etiology of nearly 30% cases of chronic viral hepatitis remains undetected. Occult HBV infection (OBI) has emerged as an important clinical entity in this scenario. Apart from prevalence and clinical outcome of OBI patients genotype was determined in northern region of India. Materials and Methods: A total of 847 patients with chronic liver disease (CLD) were screened for common viral etiologies and others serological markers of HBV. Amplifi cation of surface, precore and polymerase genes of HBV was performed in patients negative for other etiologies. Genotyping and sequencing of the precore region was performed for OBI cases. Results: Twenty-nine (7.61%) cases of OBI were identifi edof which 9 had chronic liver disease (CHD), 11 liver cirrhosis (LC) and 9 hepatocellular carcinoma (HCC). Majority of OBI cases were detected by amplifi cation of surface gene 26 (89.6%), followed by pre-core gene 12 (41.3%). Their liver functions tests were signifi cantly deranged in comparison to overt HBV cases. IgG anti HBc was present in 8 (27.6%) OBI cases. Mutation was observed in 8 (32%) in pre-core region at nt. 1896 of overt HBV cases. Genotype D was the predominant genotype. In conclusion: OBI in our study was characterized by predominance of genotype D and more severe clinical and biochemical profi le in comparison to overt HBV. IgG anti HBc positivity could be utilized as a marker of OBI. We recommend use of sensitive nested PCR for diagnosis of OBI, amplifying at least surface and precore gene.

Serum tumor necrosis factor α and C-reactive protein in pediatric patients with sepsis and its correlation with microbiologic findings.

Objective: To study the association of tumor necrosis factor-a (TNF-a) and C - reactive protein (CRP) with microbiologically documented cases of sepsis versus clinically documented cases of sepsis. Materials and Methods: Seventy nine pediatric patients with sepsis were studied. Relevant specimens were processed for bacterial or fungal etiology. TNF-a was detected by enzyme immunoassay and CRP was detected by latex agglutination. Thirty healthy cases were included in the study to establish baseline TNF-α levels. Results: Forty two (53.2%) patients had a microbiologically documented sepsis. Among Gram negative bacilli Escherichia coli was the most common isolate followed by Klebsiella spp. Staphyloccus aureus and Streptococcus pneumoniae predominated among the Gram positive cocci. Patients with a positive culture had significantly higher TNF-α levels than patients with a negative culture (70pg/ml vs. 33 pg/ml P < 0.01). Further, pure gram negative infection correlated with significantly higher TNF-α levels than pure (P < 0.01) gram positive infection. The CRP values did not highlight these differences significantly. Conclusions: TNF-α level was significantly raised in patients with sepsis. TNF-a levels were raised significantly in culture positive cases in general and in Gram negative infections in particular. Serum TNF-α was a more sensitive marker for different categories of sepsis compared to CRP and microbiology culture.

Acute lower respiratory tract infections in children.

Acute lower respiratory tract infection (ALRTI) is a common illness, but there have been relatively few studies of the bacterial etiology in developing countries. Nasopharyngeal aspirates of 70 children under 10 years of age with ALRTI were cultured for aerobic bacterial pathogens. Klebsiella pneumoniae was the commonest organism (32.2%) isolated followed by S. pneumoniae (10%), E. coli (10%), P. aeruginosa (5.7%), S. aureus (2.8%) and H. influenzae (1.4%). There were significantly more bacterial pathogens isolated in children <1 year of age (73.7%) than in those >1 year of age (56.2%) (P=0.03). A shift in spectrum from Gram-positive cocci to Gram-negative bacilli in ALRTI was observed in our study.

Changing face of septicaemia and increasing drug resistance in blood isolates.

In a retrospective study conducted between January, 2000 and December 2000, 7157 adults and children were studied. Amongst these, 1071 patients had positive blood cultures. Of these, 575 (53.6%) cases were community acquired septicaemia and 486 (46.4%) cases had developed septicaemia of nosocomial origin. Gram negative aerobes accounted for 708 (66.1%) isolates. Amongst them, Klebsiella pneumoniae predominated (23%), followed by Escherichia coli (14%). Acinetobacter spp. emerged as the next common pathogen (9%), followed by Salmonella typhi (5.4%). Staphylococcus aureus (9%) and coagulase negative staphylococci (9%) were the most common gram positive isolates followed by Enterococcus faecalis (4.7%). Antibiotic susceptibility of all these isolates was performed by the modified Stokes' method. Both Klebsiella pneumoniae and Escherichia coli showed alarmingly high resistance to all groups of antibiotics with 70-80% resistance to amoxicillin and cephalexin. Minimum resistance was observed against cefotaxime (23%) and ciprofloxacin (12%). Majority of Enterococcus faecalis were multidrug resistant. Streptococcus pneumoniae exhibited 26% resistance to penicillin. Thus, the study clearly highlights the rising level of drug resistance amongst the bacterial isolates from blood and hence the need to update and formulate newer drug policies.

Serum resistance of Escherichia coli strains causing urinary tract infection and diarrhoea in relation to alpha haemolysin production and O type.

A total of 46 alpha-hemolytic and 40 non-hemolytic clinical isolates of Escherichia coli were collected from pediatric patients with urinary tract infection and diarrhoea. Of 39 (84.7%) alpha-hemolytic strains and 27 (67.5%) non-hemolytic strains were resistant to 10% serum and there was no significant difference between urinary and stool isolates. On the contrary when 100% serum was used, 22 (47.8%) of the alpha-hemolytic and 7 (17.5%) of the non-hemolytic strains were resistant (p<0.01). and significantly greater resistance was found in urinary tract infection than from the stool samples (47% versus 24%, p<0.01). Serum resistance was higher in serogroups O6, O18 and O75. Production of alpha-hemolysin was more frequent in serogrops O2, O6, O8, O18 and O75. Thus, the resistance to human serum can determine clinical significance of Escherichia coli from different sources and alpha-hemolysin contributes to the virulence of Escherichia coli in initiation and perpetuation of clinical infection.

Killing of Escherichia coli strains from clinical specimens in human serum and polymorphonuclear leucocytes.

Hundred Escherichia coli strains were collected from extra-intestinal and intestinal disease for the present study. Of the strains isolated 49 (49%) were serum sensitive and 47 (47%) serum resistant. The remaining 4 (4%) strains showed intermediate sensitivity to the pooled normal human serum (PNHS). Strains isolated from faeces were significantly more sensitive than strains of extra-intestinal origin (P<0.01). Response of Escherichia coli strains to killing by polymorphonuclear leucocytes was seen in 50 isolates (50%). Faecal strains showed significantly more intracellular killing as compared to extra-intestinal strains (P<0.01). Thus, clinical significance of Escherichia coli strains from different sources can be determined by the resistance to the bactericidal effect of human serum and killing in polymorphonuclear leucocytes.