Ventilator-associated pneumonia.

BACKGROUND: Ventilator-associated pneumonia (VAP) is a type of nosocomial pneumonia that occurs in patients who receive mechanical ventilation (MV). According to the International Nosocomial Infection Control Consortium (INICC), the overall rate of VAP is 13.6 per 1,000 ventilator days. The incidence varies according to the patient group and hospital setting. The incidence of VAP ranges from 13-51 per 1,000 ventilation days. Early diagnosis of VAP with appropriate antibiotic therapy can reduce the emergence of resistant organisms. METHOD: The aim of this review was to provide an overview of the incidence, risk factors, aetiology, pathogenesis, treatment, and prevention of VAP. A literature search for VAP was done through the PUBMED/MEDLINE database. This review outlines VAP's risk factors, diagnostic methods, associated organisms, and treatment modalities. CONCLUSION: VAP is a common nosocomial infection associated with ventilated patients. The mortality associated with VAP is high. The organisms associated with VAP and their resistance pattern varies depending on the patient group and hospital setting. The diagnostic methods available for VAP are not universal; however, a proper infection control policy with appropriate antibiotic usage can reduce the mortality rate among ventilated patients.

Role of Appropriate Therapy in Combating Mortality among the Ventilated Patients.

CONTEXT: Ventilator associated pneumonia (VAP) is a nosocomial infection prevalent among the intensive care unit (ICU) patients despite proper infection control practices. The diagnosis of VAP still remains controversial and hence the mortality rate is higher among this group of patients. AIM: The aim of our study was to identify the antibiotic pattern and the appropriateness of treatment followed in the ICU in relation with the clinical pulmonary infection score (CPIS) as a tool to diagnose VAP. This was compared with patients who had an inappropriate treatment in comparison to the CPIS and the clinical outcome. RESULTS: Out of the 18 VAP patients, 12 (66.7%) received appropriate therapy based on the antibiotic susceptibility pattern of the causative organism, while 1 (5.5%) received partially inappropriate therapy and 5 (27.8%) received totally inappropriate therapy. Nine of the 18 (50%) VAP patients died, while only 5 of the 58 (8.6%) patients without VAP died. 72.2% patients with VAP received appropriate treatment based on the sensitivity of the isolates. The mortality rate in VAP patients receiving inappropriate therapy was 80%, while in those receiving appropriate therapy the mortality rate was 38.5%. The mortality rate among VAP patients with blood culture positivity was 100%, while it was 43.75% among those with negative blood culture. CONCLUSION: The mortality rate among the patients receiving inappropriate therapy is high compared to other group of patients. Hence, a proper evaluation and administration of appropriate antibiotics can curb mortality among the ventilated patients.

Laboratory evaluation of phenotypic detection methods of methicillin-resistant Staphylococcus aureus.

Although conventional antibiotic susceptibility tests are most commonly performed for methicillin-resistant Staphylococcus aureus (MRSA), the results of these phenotypic tests are dependent on the standardization of the culture conditions. The aim of the study was to evaluate the conventional phenotypic screening tests in comparison to the mecA gene polymerase chain reaction (PCR). One hundred and two clinical isolates of MRSA identified by the oxacillin disk diffusion were subjected to PCR for the mecA gene and by the cefoxitin disk diffusion test and culture on oxacillin screen agar, mannitol salt agar, and methicillin-resistant Staphylococcus aureus Agar (MeReSA) selective medium, for MRSA. Although all 102 isolates were resistant in oxacillin and cefoxitin disk diffusion, 92 (90.1%) isolates were positive for the mecA gene. The sensitivities of the mannitol salt agar, MeReSA agar, and oxacillin screen agar were 89.13, 97.82, and 98.91%, respectively. The oxacillin screen agar may be recommended for confirming methicillin resistance in the disk diffusion test in resource-poor settings, where molecular methods are not available.

Early dengue diagnosis by nonstructural protein 1 antigen detection: rapid immunochromotography versus two the enzyme-linked immunosorbent assay kits.

Dengue is known for its serious life-threatening complications. New rapid kits available recently in India target circulating non-structural protein (NS1) antigen from day one onwards. The sensitivity and specificity of a newly introduced rapid combo kit against two conventional ELISA kits is assessed. The performance of this kit is quite satisfactory since excellent agreement of 94.26% was observed with particular reference to NS1 antigen detection among all three kits namely Rapid SD Bioline dengue Duo (SD Korea), InBios DENV Detect NS1 ELISA, USA and dengue Early ELISA, Panbio, Australia. The false positivity of the rapid kit is very low since its specificity as for as NS1 antigen detection is concerned is 98.33%. The use of combination kit helps to detect additional cases of dengue, which are negative for NS1 antigen but positive for IgM and/or IgG antibodies, thus facilitating early diagnosis in remote areas and small laboratorie.

Changing Trends in Resistance Pattern of Methicillin Resistant Staphylococcus aureus.

BACKGROUND: Methicillin resistance in Staphylococcus aureus is associated with multidrug resistance, an aggressive course, increased mortality and morbidity in both community and health care facilities. Monitoring of newly emerging and prevalent Methicillin Resistant Staphylococcus aureus (MRSA) strains for their resistance patterns to conventional as well as novel drugs, are essential for infection control. AIMS: To study the changing trends in resistance patterns of MRSA at our hospital. SETTINGS AND DESIGN: This cross sectional study was carried out in a 750 bed tertiary care hospital in south India. MATERIAL AND METHODS: One hundred and two clinical isolates of MRSA which were obtained in 2004-2011 were identified by using oxacillin, cefoxitin disc diffusion test and oxacillin screening agar test. Antibiotic susceptibility test was done for commonly used non beta lactam anti-Staphylococcal drugs, as well as for anti-MRSA drugs like vancomycin, linezolid, mupirocin and rifampicin. Minimum inhibitory concentration (MIC) of vancomycin was determined by using Vancomycin HiComb strip (Himedia, Mumbai, India). Statistical Analysis which was done: Chi-square test and proportions were used to compare the two groups. RESULTS: MRSA isolates showed high resistance to co-trimoxazole (82.3%), ciprofloxacin (76.4%), gentamicin (64.7%) and tetracycline (49%) as compared to other drugs. High prevalence of ciprofloxacin resistance was detected, particularly among outpatients. Multi resistant MRSA with a ≥ 3 non-beta lactam agent resistance was 79%. All MRSA isolates were sensitive to vancomycin, linezolid, mupirocin and rifampicin. MRSA had displayed increase in resistance to most antibiotics except tetracycline in recent years. CONCLUSIONS: Taking into consideration the prevalence of multidrug resistance in MRSA, resistance patterns should be evaluated periodically and antibiotic therapy should be guided by susceptibility testing.

Septic Arthritis caused by Group A Streptococcus in Newborn: An Unusual Presentation.

Streptococcal sepsis in neonates is a potentially lethal condition. A wide spectrum of clinical presentations has been often reported in Group B Streptococcal infections in neonates. Bone and joint infections which are caused by Group B Streptococcus are also encountered frequently, but they have not yet been reported in case of Group A Streptococcal infection in neonates. Here, we are reporting a case of septic arthritis and late onset neonatal sepsis which were caused by Group A Streptococcus in a full term, healthy baby.

Incidence and risk factors of ventilator associated pneumonia in a tertiary care hospital.

BACKGROUND: Ventilator associated pneumonia (VAP) is a type of nosocomial pneumonia associated with increased morbidity and mortality. Knowledge about the incidence and risk factors is necessary to implement preventive measures to reduce mortality in these patients. METHOD: A prospective study was conducted at a tertiary care teaching hospital for a period of 20 months from November 2009 to July 2011. Patients who were on mechanical ventilation (MV) for more than 48 hours were monitored at frequent intervals for development of VAP using clinical and microbiological criteria until discharge or death. RESULTS: Of the 76 patients, 18 (23.7%) developed VAP during their ICU stay. The incidence of VAP was 53.25 per 1,000 ventilator days. About 94% of VAP cases occurred within the first week of MV. Early-onset and late-onset VAP was observed in 72.2% and 27.8%, respectively. Univariate analysis showed chronic lung failure, H2 blockers usage, and supine head position were significant risk factors for VAP. Logistic regression revealed supine head position as an independent risk factor for VAP. CONCLUSION: VAP occurred in a sizeable number of patients on MV. Chronic lung failure, H2 blockers usage, and supine head position were the risk factors associated with VAP. Awareness about these risk factors can be used to inform simple and effective preventive measures.

Detection of metallo-beta-lactamase producing Pseudomonas aeruginosa in intensive care units.

BACKGROUND: Metallo-beta-lactamase (MBL) producing Pseudomonas aeruginosa has emerged as a threat to hospital infection control, due to its multi-drug resistance, especially in intensive care units (ICUs). AIMS: This study was carried out to detect MBL producing P. aeruginosa isolates from medical and surgical ICUs, to compare and evaluate different phenotypic methods currently in use and to determine antibiograms. METHOD: A prospective study was undertaken to detect MBLs in P. aeruginosa isolates obtained from various clinical samples. A total of 49 strains were recovered from patients admitted in inpatient wards and ICUs, and screened for imipenem resistance by Kirby Bauer disk diffusion method. Detection of MBLs was further done by imipenem-EDTA disk synergy test and combined disk test. RESULTS: Out of 49 isolates, 11 isolates (22.4 per cent) were imipenem resistant. All 11 imipenem resistant P. aeruginosa strains, when further tested, were positive for MBL production by combined disk test, but, only eight showed positive results by imipenem-EDTA disk synergy test. CONCLUSION: MBL production was the main resistance mechanism in the 11 carbapenem resistant P. aeruginosa isolates collected, with multidrug resistance associating significantly with MBL production in P. aeruginosa from our institution.

Multi-drug resistant Acinetobacter species from various clinical samples in a tertiary care hospital from South India.

BACKGROUND: Acinetobacter species are gram-negative coccobacilli belonging to the group of Non-Fermenting Gram-Negative Bacilli, which are ubiquitous in nature. They cause outbreaks in intensive care units and healthcare settings, and are becoming increasingly drug resistant. AIMS: To determine the prevalence of multi-drug resistant Acinetobacter species from various clinical samples. METHOD: Clinical samples were processed as per standard microbiological techniques. Antibiotic susceptibility testing was carried out on all the Acinetobacter isolates by Kirby- Bauer disc diffusion method as per CLSI guidelines. RESULTS: A total of 122 Acinetobacter spp. were isolated. 110 (90.16 per cent) were from inpatients, and 12 (9.83 per cent) were from outpatients. Out of 122 isolates, 44 (36.06 per cent) were from the ICU. The majority of the isolates, 47 (38.52 per cent), were from pus samples followed by 25 (20.49 per cent) from endotracheal tube aspirate. Out of 122 isolates, 87 (71.31 per cent) were multi-drug resistant of which 15 (12.29 per cent) were resistant to all drugs tested. CONCLUSION: Acinetobacter infections associated with multi-drug resistant and pan-resistant strains have emerged as important nosocomial pathogens in our setting.

Detection of extended spectrum beta lactamases, ampc beta lactamases and metallobetalactamases in clinical isolates of ceftazidime resistant Pseudomonas Aeruginosa

We studied the prevalence of ceftazidime resistance in Pseudomonas aeruginosa and the rates of extended-spectrum β-lactamase (ESBL), AmpC β-lactamase (AmpC) and metallo-β-lactamase (MBL) production among the ceftazidime resistant Pseudomonas aeruginosa. A very high rate of MBL production was observed, which suggested it to be an important contributing factor for ceftazidime resistance among Pseudomonas aeruginosa.

Anterior abdominal wall abscess caused by Streptococcus pneumoniae in a patient with self-inflicted stab injury: An unusual presentation.

Streptococcus pneumoniae is a major cause of community-acquired pneumonia, otitis media, paranasal sinusitis, bacteremia and meningitis, as well as osteomyelitis and occasionally peritonitis. We report the case of a 25-year-old female who had stabbed herself with a kitchen knife above the umbilicus 10 days prior to admission. Subsequently, she developed an anterior abdominal wall abscess caused by S. pneumoniae. This case is unusual as the focus was distant from the respiratory tract, the usual primary site of infection caused by this organism. Furthermore, the case assumes significance because it occurred in the absence of any typical risk factors for S. pneumoniae.

Detection of extended spectrum beta lactamases, ampc beta lactamases and metallobetalactamases in clinical isolates of ceftazidime resistant Pseudomonas Aeruginosa.

We studied the prevalence of ceftazidime resistance in Pseudomonas aeruginosa and the rates of extended-spectrum ß-lactamase (ESBL), AmpC ß-lactamase (AmpC) and metallo-ß-lactamase (MBL) production among the ceftazidime resistant Pseudomonas aeruginosa. A very high rate of MBL production was observed, which suggested it to be an important contributing factor for ceftazidime resistance among Pseudomonas aeruginosa.

Multifocal keloids associated with Mycobacterium fortuitum following intralesional steroid therapy.

We report a case of subcutaneous abscess formation with Mycobacterium fortuitum following intralesional steroid injection into multifocal keloids. A high index of suspicion of atypical mycobacteria infection is needed in patients with a history of skin and soft tissue infections, in particular late-onset infections, which are negative for routine bacterial cultures and without a clinical response to antibiotics used for acute pyogenic infections.