Recurrent sternal wound infection caused by Gordonia bronchialis after open heart surgery.

Gordonia bronchialis is an aerobic gram-positive bacilli and also weakly acid fast. It requires a long incubation time and extensive biochemical reactions for identification. Therefore, use of broad-range polymerase chain reaction (PCR) for amplification of genes such as 16S rRNA or hsp65 followed by sequencing or advanced techniques like MALDI-TOF MS is needed for identification. Here, we present a case of persistent sternal wound infection following open heart surgery, caused by G. bronchialis in a 58 years old male, identified using MALDI-TOF MS-based system. The patient improved with oral Cefpodoxime 200 mg BD for four weeks.

Outcome of ventilator-associated pneumonia: Impact of antibiotic therapy and other factors.

BACKGROUND: Ventilator-associated pneumonia (VAP) is the most frequent infection in patients intubated for longer than 48 hours. There is a great interest in determining the factors influencing the outcome of VAP, as it may help in reducing the associated morbidity and mortality. This study aimed to determine the impact of appropriate antibiotic therapy based on endotracheal aspirate cultures on the outcome of VAP. We have also studied the other factors that may influence the outcome of VAP. METHOD: A cohort study was conducted in the intensive care units of a tertiary care hospital in South India over a period of 15 months. The outcome of VAP was assessed by prolongation of the duration of mechanical ventilation and/or death of the patient. RESULTS: The duration of mechanical ventilation was significantly prolonged in patients with VAP (16.61 ± 8.2 d vs. 8.21 ± 5.9 d, P < 0.0001). VAP patients receiving partially or totally inappropriate therapy (defined as lack of coverage of one or all the significant VAP pathogens) were at significantly high risk for death (Relative risk, 2.00; 95% confidence interval, 1.14 to 3.52; P 0.0008). A delay of > 2 days in administering the first dose of appropriate antibiotic therapy significantly prolonged the duration of ventilation (P < 0.0001). Infection by multi-drug resistant pathogens, polymicrobial infection and time of onset of VAP did not have significant impact on the outcome of VAP. CONCLUSION: Early administration of appropriate antibiotic therapy, based on the antibiogram of the VAP pathogens identified by quantitative culture of endotracheal aspirate, could lead to an improved outcome of patients with ventilator-associated pneumonia.

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.

Role of intensive care unit environment and health-care workers in transmission of ventilator-associated pneumonia.

BACKGROUND: Pseudomonas aeruginosa and Acinetobacter baumannii have been reported to cause outbreaks of ventilator-associated pneumonia (VAP) in several studies. The high prevalence of these pathogens prompted us to study the different strains of these pathogens prevailing in our intensive care units (ICUs) and determine the role of ICU environment and health-care workers (HCWs) in the transmission of infection. METHODOLOGY: A prospective study was performed over a period of 15 months in two ICUs of Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, India. Surveillance samples were collected from the HCWs and the ICU environment. Quantitative antibiogram typing and PCR-RFLP were used for comparison of the isolates from the surveillance samples and VAP patients. RESULTS: Pseudomonas aeruginosa and Acinetobacter baumannii were the most common potential VAP pathogens isolated from the surveillance cultures. Eight strains of Pseudomonas aeruginosa were present in our ICUs, but multi-drug resistant (MDR) strain 2 and strain 4 were the most prevalent strains. Six strains of Acinetobacter baumannii were found in our ICUs, of which MDR strain 1 and strain 3 were the most common. The strains of Pseudomonas aeruginosa and Acinetobacter baumannii observed in the VAP patients were also found in the ICU milieu. Only one HCW was found to be the carrier of a Pseudomonas aeruginosa strain present in a VAP patient. CONCLUSIONS: The ICU environment was observed to be the potential reservoir for VAP pathogens; therefore, strict adherence to environmental infection control measures is essential to prevent health-care-associated infections.

Ventilator-associated pneumonia in a tertiary care hospital in India: role of multi-drug resistant pathogens.

BACKGROUND: Ventilator-Associated Pneumonia (VAP) is the most frequent intensive-care-unit (ICU)-acquired infection. The aetiology of VAP varies with different patient populations and types of ICUs. METHODOLOGY: A prospective study was performed over a period of 15 months in a tertiary care hospital to determine the various aetiological agents causing VAP and the prevalence of multidrug resistant (MDR) pathogens. Combination disk method, Modified Hodge test, EDTA disk synergy (EDS) test and AmpC disk test were performed for the detection of extended spectrum beta-lactamases (ESBL), carbapenemases, metallo-beta-lactamases (MBL) and AmpC beta-lactamases respectively. RESULTS: Enterobacteriaceae, Haemophilus influenzae, Staphylococcus aureus, Streptococcus pneumoniae, Candida spp. were more common in early-onset VAP, while non-fermenters (Pseudomonas spp. and Acinetobacter spp.) were significantly associated with late-onset VAP (P value 0.0267, Chi-square value 4.91). Thirty-seven (78.7%) of the 47 VAP pathogens were multidrug resistant. ESBL was produced by 50% and 67% of Escherichia coli and Klebsiella pneumoniae respectively. MBL was produced by 20% of P. aeruginosa. AmpC beta-lactamases were produced by 33.3% and 60.7% of the Enterobacteriaceae and non-fermenters respectively. Of the S. aureus isolates, 43% were methicillin resistant. Prior antibiotic therapy and hospitalization of five days or more were independent risk factors for VAP by MDR pathogens. CONCLUSIONS: VAP is increasingly associated with MDR pathogens. Production of ESBL, AmpC beta-lactamases and metallo beta-lactamases were responsible for the multi-drug resistance of these pathogens. Increasing prevalence of MDR pathogens in patients with late-onset VAP indicate that appropriate broad-spectrum antibiotics should be used to treat them.