Clinical profile, visual outcome and root cause analysis of post-operative cluster endophthalmitis due to Burkholderia cepacia complex

Purpose: To present varied clinical presentations, surveillance reports, and final visual outcomes of a rare outbreak of cluster endophthalmitis caused by gram?negative, opportunistic bacilli, Burkholderia cepacia complex (Bcc). Methods: Details of five patients who developed postoperative cluster endophthalmitis were collected. For each patient, an undiluted vitreous sample was collected during vitreous tap. Bacterial culture from the vitreous sample in each case had grown Bcc. Surveillance investigations for root cause analysis (RCA) were performed in the operating room (OR), admission, and day?care wards to localize the source. Results: Four patients had undergone phacoemulsification surgery, and one patient had undergone penetrating keratoplasty. Each patient received an initial dose of empiric intravitreal ceftazidime and vancomycin. The organism isolated in each case was sensitive to ceftazidime, cotrimoxazole, and meropenem and resistant to other antibiotics. Core vitrectomy was done after 48–60 hours in four patients along with intravitreal imipenem injection. One patient did not provide consent for core vitrectomy and subsequently developed phthisis bulbi. Three patients had subsequent recurrences. Two patients had a final BCVA of 20/60, two had BCVA better than 20/200, while one patient had no perception of light. None of the surveillance samples from the OR complex could isolate Burkholderia. Conclusion: Extensive OR surveillance should be done to identify the potential source of infection. However, the source may not be identifiable in few instances like in our case. Longer follow?up is recommended in cases of Bcc endophthalmitis due to the persistent nature of the infection

Evaluation of colorimetric nitrate reductase assay for rapid detection of methicillin resistance in clinical isolates of Staphylococcus aureus.

Background & objectives: Methicillin resistant Staphylococcus aureus (MRSA) remains a major cause of health care-associated infections. Rapid detection of MRSA facilitates the early initiation of appropriate treatment and infection control. Hence, the present study was undertaken to standardize and evaluate the performance of rapid colorimetric nitrate reductase assay (NRA) for determining methicillin resistance in S.aureus. Methods: A total of 160 clinical isolates of S. aureus, (80 each of methicillin susceptible and methicillin resistant) were included in the study. Minimum inhibitory concentration (MIC) was determined by NRA and reference broth micro dilution (BMD) methods. Results of NRA were compared with BMD and analyzed. Results: For MRSA, the MIC values ranged from 4 to ≥ 16 μg/ml and for MSSA, ≤ 0.5 to 2 μg/ml. Category and essential agreement for NRA as compared with BMD were found to be 99.4 and 89.7 per cent, respectively. No minor or major discrepancy was observed. A single resistant isolate showed very major discrepancy. Interpretation & conclusions: Colorimetric NRA being an inexpensive test requiring no special equipment can be employed as an alternative method for rapid detection of MRSA in resource limited settings.

Risk Factors Associated with Methicillin-resistant Staphylococcus aureus Infection in Children.

Objective: To identify the clinical variables that differentiate MRSA (Methicillin-resistant Staphylococcus aureus) from MSSA (Methicillin-sensitive S. aureus) infection. Methods: Cases having culture isolates of Staphylococcus species were recruited. Baseline and other laboratory parameters were compared between MSSA and MRSA sub-groups to identify the predictors for MRSA. Results: Out of 98 isolates of S.aureus, 46 (47%) were MRSA. Significant leukocytosis was found in cases with MRSA (P <0.03). None of the other clinical variables could differentiate MRSA from MSSA infection. Conclusion: Presence of leukocytosis was twice more likely to predict MRSA than MSSA at admission. Empiric therapy must be guided by antimicrobial sensitivity pattern of regional culture isolates.

Epidemiology of influenza viruses from 2009 to 2013 - A sentinel surveillance report from Union territory of Puducherry, India

Objective: To report the findings of influenza surveillance programme from Union territory of Puducherry and to document the clinical and epidemiological data of influenza viruses over a five year period from 2009 to 2013. Methods: Respiratory samples were collected from patients with influenza-like illness from 2009 to 2013 as part of routine diagnostic and surveillance activity. Detection of pandemic influenza A (H1N1) 2009, influenza A (H3N2) and influenza B was done using Real-time PCR. Results: Of the total 2. 247 samples collected from patients with influenza-like illness during the study period 287 (12.7%) and 92 (4.0%) were positive for influenza A (H1N1) 2009 and influenza A (H3N2) respectively. A subset of 557 of these samples were also tested for influenza B and 24 (4.3%) were positive. Significantly higher positivity rate for both viruses was observed in adults when compared with children. The peak positivity of influenza A (H1N1) 2009 was observed in 2009 followed by 2012, while that of influenza A (H3N2) was more uniformly distributed with the exception of 2012. Overall mortality rate due to influenza A (H1N1) 2009 was 7.6% while it was 1% for influenza A (H3N2). Each year influenza-like illness and influenza virus activity coincided with period of high rainfall and low temperature except in the first half of 2012. Conclusions: As the sole referral laboratory in this region, the data provides a comprehensive picture of influenza activity. This information will be useful in future planning of the vaccine schedule and influenza pandemic preparedness.

Epidemiology of influenza viruses from 2009 to 2013 - A sentinel surveillance report from Union territory of Puducherry, India

OBJECTIVE@#To report the findings of influenza surveillance programme from Union territory of Puducherry and to document the clinical and epidemiological data of influenza viruses over a five year period from 2009 to 2013.@*METHODS@#Respiratory samples were collected from patients with influenza-like illness from 2009 to 2013 as part of routine diagnostic and surveillance activity. Detection of pandemic influenza A (H1N1) 2009, influenza A (H3N2) and influenza B was done using Real-time PCR.@*RESULTS@#Of the total 2247 samples collected from patients with influenza-like illness during the study period 287 (12.7%) and 92 (4.0%) were positive for influenza A (H1N1) 2009 and influenza A (H3N2) respectively. A subset of 557 of these samples were also tested for influenza B and 24 (4.3%) were positive. Significantly higher positivity rate for both viruses was observed in adults when compared with children. The peak positivity of influenza A (H1N1) 2009 was observed in 2009 followed by 2012, while that of influenza A (H3N2) was more uniformly distributed with the exception of 2012. Overall mortality rate due to influenza A (H1N1) 2009 was 7.6% while it was 1% for influenza A (H3N2). Each year influenza-like illness and influenza virus activity coincided with period of high rainfall and low temperature except in the first half of 2012.@*CONCLUSIONS@#As the sole referral laboratory in this region, the data provides a comprehensive picture of influenza activity. This information will be useful in future planning of the vaccine schedule and influenza pandemic preparedness.

Community acquired secondary bacterial peritonitis in a tertiary hospital of South India: an audit with special reference to peritoneal fluid culture.

Background: This study was conducted to elucidate the spectrum of community acquired acute bacterial peritonitis, the role of microbiological culture in its management and other factors affecting its outcome. Methods: This was a prospective study wherein we examined cases of secondary bacterial peritonitis admitted and operated at our institution from January 2005 to May 2006. The peritoneal fluid was sent for bacterial culture and sensitivity testing. Patients were followed up with relevant progress details till discharge or death. Results: We enrolled 352 patients. The mean age of the study population was 42.4 years with a male:female ratio of 7:1. Gastroduodenal perforations formed the major site of perforation (51%), followed by small bowel (29%) and appendicular perforations (17%). Culture positivity rate was 64%. Escherichia coli and Klebsiella species were the predominant isolates from peritoneal fluid. These main isolates were predominantly sensitive to ceftazidime, amikacin and chloramphenicol. Ampicillin with gentamicin and metronidazole was the first line of treatment used preoperatively in 67% of the patients, given its low cost and easier availability. The overall morbidity and mortality rates were 52% and 16.5% respectively. 78% of patients received inadequate antibiotics preoperatively. Only 26% had appropriate change of antibiotics postoperatively. Conclusions: There was no significant benefit of postoperative change of antibiotics based on culture results. Analysis of factors influencing mortality shows dominance of host related factors over the type and source of infection with high risk population identified by age>60 years, delayed presentations>3 days and APACHE II score>15.

Fatal Delftia acidovorans infection in an immunocompetent patient with empyema

Delftia acidovorans (earlier known as Comamonas acidovorans) is an aerobic, non-fermentative, Gram negative rod, classified in the Pseudomonas rRNA homology Group III. Reports of isolation of the organism from serious infections like central venous catheter associated bacteremia, corneal ulcers, otitis media exist. The microbiologists can identify this organism based on an orange indole reaction. This reaction demonstrates the organism's ability to produce anthranilic acid from tryptophan on addition of Kovac's reagent; which gives the media its characteristic“pumpkin orange” colour. Here we report the isolation of this organism from the Endotracheal tube aspirate of a 4 year old child. With the increasing use of invasive devices, it has become important to recognize these non fermentative gram negative bacilli as emerging source of infection even in immunocompetent individuals.

Reliability of Kirby-Bauer disk diffusion method for detecting meropenem resistance among non-fermenting gram-negative bacilli.

Background: Meropenem is empirically used as a last resort for the treatment of infections by non-fermenting gram-negative bacilli (NFGNB). Minimum inhibitory concentration (MIC) determined using agar or broth dilution methods is widely used for testing meropenem resistance. However, it is not possible in resource-poor settings. Aim: A prospective study was performed to evaluate the reliability of Kirby-Bauer disk diffusion (KBDD) method for detecting meropenem resistance among NFGNB. Materials and Methods: A total of 146 NFGNB consisting of 56 Acinetobacter baumannii, 24 Acinetobacter lwoffii, 48 Pseudomonas aeruginosa and 18 Pseudomonas spp. were included in the study. All the isolates were tested simultaneously by both KBDD method and agar dilution method. Results: Very major errors were not observed with A. baumannii, A. lwoffii and P. aeruginosa, while other Pseudomonas spp. showed a very major error rate of about 5.6%. The major error rates observed with A. baumannii, A. lwoffii, P. aeruginosa and Pseudomonas spp. were 1.8%, 0%, 2.1% and 28.6%, respectively. All the isolates showed a good correlation between zone diameters (KBDD method) and MICs (agar dilution method). The sensitivity and specificity of KBDD method for detecting meropenem resistance was above 90% for all the NFGNB except Pseudomonas spp. Conclusions: The KBDD method can be reliably used for routine testing of meropenem resistance in A. baumannii, A. lwoffii and P. aeruginosa. However, further studies are needed before employing this technique for detecting meropenem resistance in Pseudomonas spp.

Acute osteomyelitis caused by Rhodococcus equi in an immunocompetent child.

Rhodococcus equi is an unusual pathogen causing infections mostly in immunocompromised patients, particularly in those with human immunodeficiency virus (HIV). It has rarely been reported to affect immunocompetent hosts, where it usually presents as an isolated extrapulmonary lesion. We report a case of osteomyelitis caused by this organism in an immunocompetent host.