Biliary tract infections and their Microbiological Spectrum- A study from coastal region of Southern India / Infecciones de vías biliares y su espectro microbiologico- Un estudio en región de la costa del sur de la India

Objective: Biliary tract infections include cholangitis and cholecystitis. They are associated with high morbidity and mortality in elderly patients with co-morbid disease. The present study was undertaken to determine the microbial aetiology causing biliary tract infections and also to study their antimicrobial resistance profile. Materials & methods: A retrospective study was conducted from January 2011 to December 2016 at the Enteric Diseases Division, Kasturba Medical College Hospital, Manipal. Patients with biliary tract infections admitted in tertiary referral health care hospital, Manipal were included for the study. Aerobic and anaerobic bacteriological and fungal aetiology of biliary tract infections were recorded along with their antimicrobial resistance profile. Results: Out of 307 bile samples sent for aerobic culture and susceptibly testing 187 (60.91%) were positive for culture, of which Escherichia coli (44.4%) was the predominant aetiology followed by Klebsiella pneumoniae (27.3%). Among the 14 samples sent for anaerobic culture, 5 (35.75%) specimens showed growth, of which Bacteroides fragilis group was found to be the predominant anaerobe. Among the 201 bacterial pathogens tested for their antimicrobial susceptibility, 108 (53.73%) isolates were resistant, out of which 9 were PDR Enterobacteriaceae with 12 ESBL strains. All the Candida species were susceptible to fluconazole with the exception of C. glabrata and C. krusei. All the anaerobic isolates were found to be susceptible to Metronidazole. Conclusions: The high rate of bacterial infection particularly gram-negative bacteria was recorded. It is necessary that antimicrobial therapy be initiated when culture or the clinical conditions reports caution. Routine aerobic and anaerobic culturing of bile samples with biliary tract infections are imperatively necessary. With the emergence of multidrug resistant pathogens and change in the microbiological spectrum of biliary tract infections, there is a need for the empirical antimicrobial therapy in every clinical setting.

Objectivo: Las infecciones del tracto biliar incluyen colangitis y colecistitis. Se asocian a gran mortalidad y morbildiad en pacientes ancianos y con comorbilidad. El presente studio se hizo para detemrianr la etiologia microbiana que produce infecciones biliares y para estudiar su perfil de resistencia antimicrobiana. Materiales & metodos: Se hizo un studio retrospectivo entre los meses de Enero 2011 a Diciembre de 2016 en la "Enteric Diseases Division, Kasturba Medical College Hospital, Manipal" en India. Los pacientes con infección de vías biliares admitidos al centro de atención de tercer nivel se incluyeron en el estudio. Se buscaron bacterias aerobicas y anaerobicas y etiologia fungica y se analizó su perfil de resistencia antibiotica. Resultados: De 307 muestras de bilis enviadas para cultivo aerobico y antibiograma, 187 (60.91%) crecieron en el medio de cultivo, predominando Escherichia coli (44.4%) seguida por Klebsiella pneumoniae (27.3%). Entre las 14 muestras analizadas en medio anaerobio, 5 (35.75%) mostraron crecimiento de Bacteroides fragilis. Entre 201 bacterias probadas por antibiograma, 108 (53.73%) tuvieron perfil de resistencia, de los cuales 9 fueron PDR Enterobacteriaceae con 12 cepas ESBL. Todas las especies de Candida fueron susceptibles al fluconazol con la excepción de C. glabrata y C. krusei. Todos los aislados anaerobios fueron susceptibles al Metronidazol. Conclusiones: Se encontró una alta tasa de infección bacteriana con predominio de gram-negativos. Se hace necesario iniciar terapia antimicrobiana cuando lo sugieren las condiciones clínicas o el resultado del cultivo. El cultivo rutinario de bilis es imperioso. Dado el aumento de patógenos multirresistentes se requiere inicio empírico inmediato

Slime production a virulence marker in Pseudomonas aeruginosa strains isolated from clinical and environmental specimens: a comparative study of two methods.

Detection of slime in Pseudomonas aeruginosa can be useful in understanding the virulence of this organism. Here, comparative studies of two phenotypic methods using the tube method and the spectrophotometric method for slime production from 100 clinically and 21 environmentally significant isolates of P. aeruginosa were performed. A total of 68 isolates were positive by either of the tests whereas only 34 were positive by both the tests. The tube method detected slime significantly in more number of isolates than the spectrophotometric method. The tube test was found to be superior to the spectrophotometric method in ease of performance, interpretation and sensitivity. Among the clinical isolates, systemic isolates produce less slime compared to wound, respiratory and urinary isolates. Isolates from the hospital environment produced more slime indicating that this virulence marker helps the organism to survive for longer periods and cause nosocomial infections.

Identification of enteroaggregative Escherichia coli in infants with acute diarrhea based on biofilm production in Manipal, south India.

Background: Enteroaggregative Escherichia coli (EAEC) is an emerging enteric pathogen that causes persistent diarrhea among infants, both in developing and industrialized countries. The EAEC strains adhere to epithelial cell surface, to the glass substratum and to each other in a distinctive stacked brick-formation. Thus, gold standard for identification of EAEC remains the HEp-2 cell adherence test, which is time consuming and requires specialized facilities. Aim: To evaluate the usefulness of quantitative biofilm assay to screen for EAEC from children with acute diarrhea. Materials and Methods: A total of 100 E. coli strains were collected from acute diarrheal cases from December 2005 to November 2006. The strains were screened for biofilm production using microtiter plate method. The biofilm in the microtiter plate was visualized after staining with crystal violet and was quantified using enzyme immunosorbent assay plate reader. The Aggregative plasmid and Heat stable toxin genes were evaluated by a multiplex polymerase chain reaction. The strains were identified as EAEC with an optical density at 570 nm (OD 570 ) > 0.2. Results: Of the total 100 Escherichia coli strains, 28 were positive by Polymerase Chain Reaction for two genes, AggR and EAST. Of the 28 PCR-positive strains screened for biofilm, 25 (89.2%) showed positive results by microtiter plate method. Conclusion: The quantitative biofilm assay using microtiter plate is convenient and economical and can be used as a screening method to screen E. coli isolates from acute diarrheal cases. The best use of this test is to screen large number of isolates quickly, and if positive this can be confirmed by multiplex PCR for AggR and EAST genes. This assay may contribute to demonstrating the true incidence of EAEC with and without AggR among clinically isolated E. coli strains, which can cause acute diarrhea.

Paraffin baiting system for demonstration of growth and biofilm production in Pseudomonas aeruginosa.

Pseudomonas aeruginosa is one of the commonest pathogens among the pseudomonads. This organism can grow in minimal nutritional requirements. Because of the ability of pseudomonads to grow on paraffin is not commonly found among other human pathogens and the primary human pathogen being P. aeruginosa, we studied the adaptation of this organism to paraffin baiting system for growth and biofilm formation. Strains were tested for the capacity to use paraffin as the sole source of carbon using Czapek's minimal salt medium. Of the 53 clinical isolates of P. aeruginosa, 20 strains exhibited growth by 24 hrs and 42 strains by 48 hrs. The remaining strains did not show any growth in the paraffin baiting system. The oxidase test with the paraffin baiting system was also performed. This simple and inexpensive method can be used to isolate and demonstrate the biochemical and biofilm forming capacity of the organism.

Induction of resistance to fluoroquinolones in clinical and environmental isolates of Pseudomonas aeruginosa.

An attempt to induce resistance to ciprofloxacin in vitro was made against clinical and environmental isolates of Pseudomonas aeruginosa. This in vitro manipulation of strains resulted in the increase of minimum inhibitory concentration from 0.4 microg/ml to 1 microg/ml of the original strains to 9.0 to 12.5 microg/ml indicating development of resistance to ciprofloxacin and a major decrease in the size of zone diameters of norfloxacin and ofloxacin indicating cross resistance to these agents. Results indicate the induced resistance to ciprofloxacin can promote development of cross resistance to other fluoroquinolones. This suggests that caution should be taken while using fluoroquinolones for the treatment of Pseudomonas aeruginosa infections.

Biochemical identification of Enteroaggregative Escherichia Coli among infants with acute Diarrhea from Manipal, India

Background: The EAEC strains have been associated classically with persistent diarrhea which represents a disproportionate share of diarrheal mortality. EAEC strains have been shown to elicit damage to intestinal mucosa and growth retardation in infants. Detection of EAEC strains can make a significant contribution to public health in many areas. The use of biofilm assays as a screening method for EAEC from clinical isolates and multiplex PCR as confirmatory method may be useful

Methods: We evaluated the usefulness of quantitative micro titer plate method for biofilm production and multiplex PCR to screen and confirm EAEC from a total of 100 E.coli strains from children below two years of age with acute diarrhea

Results: E.coli strains were isolated from fecal specimens from 680 Diarrheic children who attended an out patient clinic or who were admitted to Kasturba Hospital and other peripheral hospitals in and around Manipal, Karnataka-South India. E coli isolates from 50 fecal specimens from infants without diarrhea [controls] who attended the same outpatient clinic and who belonged to the same group as the infants with diarrhea were also examined

Conclusion: Better diagnostic tools are needed to allow for more standardized laboratory testing on a regular basis. Improved diagnostic tools will help identify epidemiologic patterns of illness and guide treatment recommendations of EAEC illness

Biochemical identification of enteroaggregative escherichia coli among infants with acute diarrhea from Manipal, India

The EAEC strains have been associated classically with persistent diarrhea which represents a disproportionate share of diarrheal mortality. EAEC strains have been shown to elicit damage to intestinal mucosa and growth retardation in infants. Detection of EAEC strains can make a significant contribution to public health in many areas. The use of biofiim assays as a screening method for EAEC from clinical isolates and multiplex PCR as confirmatory method may be useful. We evaluated the usefulness of quantitative micro titer plate method for biofiim production and multiplex PCR to screen and confirm EAEC from a total of 100 E.coli strains from children below two years of age with acute diarrhea. E.coli strains were isolated from fecal specimens from 680 Diarrheic children who attended an out patient clinic or who were admitted to Kasturba Hospital and other peripheral hospitals in and around Manipal, Karnataka-South India. E coli isolates from 50 fecal specimens from infants without diarrhea [controls] who attended the same outpatient clinic and who belonged to the same group as the infants with diarrhea were also examined. Better diagnostic tools are needed to allow for more standardized laboratory testing on a regular basis. Improved diagnostic tools will help identify epidemiologic patterns of illness and guide treatment recommendations of EAEC illness

Rotavirus and enteric pathogens in infantile diarrhoea in Manipal, South India.

The etiology of Rotavirus in acute diarrhoeal illness in children 0-5 years of age, admitted to the pediatric wards of Kasturba Medical College Hospital, Manipal was studied over a period of 5 years. Rotavirus in the faeces detected by Latex agglutination test accounted for 19.56% of the diarrhoea with maximum incidence (65%) in the 7-12 months of age group. Bacterial aetiological agents continued to play a significant role (69.6%) in diarrhoeal diseases. Enteroaggregative E. coli was common in the age group between 25-36 months, Shigellosis in 37-60 months and Salmonella typhimurium enteritis in 7-12 months of age. The other pathogens isolated were vibrio cholerae (4.98%), species of aeromonas (15.92%), along with cryptosporidium (6.47%) and candida albicans (3.98%). In a control group consisting of 100 children without history of diarrhoea, 2 were positive for rotavirus, 3 for cryptosporidium and 12 for Escherichia coli.