Conventional vs Short Duration of Antibiotics in Patients With Moderate or Severe Cholangitis: Noninferiority Randomized Trial.

INTRODUCTION: Successful biliary drainage and antibiotics are the mainstays of therapy in management of patients with acute cholangitis. However, the duration of antibiotic therapy after successful biliary drainage has not been prospectively evaluated. We conducted a single-center, randomized, noninferiority trial to compare short duration of antibiotic therapy with conventional duration of antibiotic therapy in patients with moderate or severe cholangitis. METHODS: Consecutive patients were screened for the inclusion criteria and randomized into either conventional duration (CD) group (8 days) or short duration (SD) group (4 days) of antibiotic therapy. The primary outcome was clinical cure (absence of recurrence of cholangitis at day 30 and >50% reduction of bilirubin at day 15). Secondary outcomes were total days of antibiotic therapy and hospitalization within 30 days, antibiotic-related adverse events, and all-cause mortality at day 30. RESULTS: The study included 120 patients (the mean age was 55.85 ± 13.52 years, and 50% were male patients). Of them, 51.7% patients had malignant etiology and 76.7% patients had moderate cholangitis. Clinical cure was seen in 79.66% (95% confidence interval, 67.58%-88.12%) patients in the CD group and 77.97% (95% confidence interval, 65.74%-86.78%) patients in the SD group ( P = 0.822). On multivariate analysis, malignant etiology and hypotension at presentation were associated with lower clinical cure. Total duration of antibiotics required postintervention was lower in the SD group (8.58 ± 1.92 and 4.75 ± 2.32 days; P < 0.001). Duration of hospitalization and mortality were similar in both the groups. DISCUSSION: Short duration of antibiotics is noninferior to conventional duration in patients with moderate-to-severe cholangitis in terms of clinical cure, recurrence of cholangitis, and overall mortality.

Empirical cefepime+vancomycin versus ceftazidime+vancomycin versus meropenem+vancomycin in the treatment of healthcare-associated meningitis: results of the multicenter ephesus study.

BACKGROUND: Herein, we analyzed the efficacy of main antibiotic therapy regimens in the treatment of healthcare-associated meningitis (HCAM). MATERIALS/METHODS: This retrospective cohort study was conducted in 18 tertiary-care academic hospitals Turkey, India, Egypt and Romania. We extracted data and outcomes of all patients with post-neurosurgical meningitis cases fulfilling the study inclusion criteria and treated with empirical therapy between December 2006-September 2018. RESULTS: Twenty patients in the cefepime + vancomycin-(CV) group, 31 patients in the ceftazidime + vancomycin-(CFV) group, and 119 patients in the meropenem + vancomycin-(MV) group met the inclusion criteria. The MV subgroup had a significantly higher mean Glasgow Coma Score, a higher rate of admission to the intensive care unit within the previous month, and a higher rate of antibiot herapy within the previous month before the meningitis episode (p < 0.05). Microbiological success on Day 3-5, end of treatment (EOT) clinical success (80% vs. 54.8%% vs 57.9%), and overall success (EOT success followed by one-month survival without relapse or reinfection 65% vs. 51.6% vs. 45.3%), EOT all cause mortality (ACM) and day 30 ACM (15% vs. 22.6% vs. 26%) did not differ significantly (p > 0.05) among the three cohorts. No regimen was effective against carbapenem-resistant bacteria, and vancomycin resulted in an EOT clinical success rate of 60.6% in the methicillin-resistant staphylococci or ampicillin-resistant enterococci subgroup (n = 34). CONCLUSIONS: Our study showed no significant difference in terms of clinical success and mortality among the three treatment options. All regimens were ineffective against carbapenem-resistant bacteria. Vancomycin was unsuccessful in approximately 40% of cases involving methicillin-resistant staphylococci or ampicillin-resistant enterococci.

Genomic insights into evolution of extensive drug resistance in Stenotrophomonas maltophilia complex.

We report first complete genomic investigation of extensive drug resistance (XDR) in a nosocomial Stenotrophomonas maltophilia complex strain that is resistant to mainstream drugs (trimethoprim/sulfamethoxazole and levofloxacin). Comprehensive genomic investigation revealed its exclusive fourteen dynamic regions and highly enriched resistome comprising of two sulfonamide resistance genes on two diverse super-integrons of chromosomal origin. In addition, both these integrons harbour array of antibiotic resistance and commonly used disinfectant's resistance genes linked to ISCR elements. Isolation of a novel XDR strain from Indian tertiary care unit belonging to novel ST with diverse array of resistance genes on ISCR linked super-integrons indicates extent and nature of selection pressure in hospitals. Since, repetitive elements have major role in their spread and due to limitations of draft genomes, there is an urgent need to employ complete genome-based investigation for tracking the emergence of XDR at global level and designing strategies of antimicrobial stewardship and disinfection. IMPORTANCE: Hospital settings in India have one of the highest usages of antimicrobials and a heavy patient load. We hereby report a novel clinical isolate of S. maltophilia complex with two super-integrons that harbour array of antimicrobial resistance genes along with biocide and heavy metal resistance genes. Further, the presence of ISCR type of transposable elements on both the integrons indicates their propensity to transfer resistome while their chromosomal origin suggests possibilities for further genomic/phenotypic complexities according to selection pressure. Such complex mobile cassettes in a novel strain is a potential threat to global health care. Hence, to understand the evolution of opportunistic nosocomial pathogen, there is an urgent need to employ cost-effective long read technologies to keep vigilance on novel and XDR pathogens in populous countries. There is also need for surveillance of the usage of disinfectants and other antimicrobials for environmental hygiene and linked/rapid co-evolution of XDR in nosocomial pathogens. Repositories: Complete genome sequence of Stenotrophomonas maltophilia SM866: CP031058.

Microorganisms Profile and Antimicrobial Resistance Pattern in Outborn Neonates in Northern India: A Hospital-Based Observational Study.

BACKGROUND: Neonates born somewhere else (outborn) and treated in a referral centre have different microbiological profile. We report the microorganism's profile and antimicrobial resistance (AMR) in blood culture proven sepsis in outborn neonates. METHODS: Culture positive neonatal sepsis from a neonatal unit of a referral institute catering to outborn neonates was studied over an 18 months duration. Data from the hospital information system were used to analyse the culture positivity rates, the spectrum of the microorganisms isolated and AMR pattern. RESULTS: Out of 5258 admitted neonates, 3687 blood samples were sent for suspect sepsis. The blood cultures were positive in 537 (14.6%) samples from 514 neonates. Gram-positive cocci (GPC) were the most common [240 (45%)] followed by gram-negative bacilli (GNB) [233 (43.4%)] and fungi [64 (11.9%)]. Coagulase negative staphylococcus (CONS) contributed to two-thirds of GPC followed by Klebsiella [93 (17.3%)] and Acinetobacter species [52 (9.7%)]. In 403 (75%) neonates, organisms grew in the samples sent at or within 24 h of admission. The case fatality rate was significantly higher in those with culture positive sepsis. The resistance to meropenem and imipenem was documented in 57.1% and 49.7%, respectively and 48% of the GNB was multidrug resistant. CONCLUSIONS: CONS followed by Klebsiella species were the most common organisms isolated. Three-fourths of the neonates had organisms grown at or within 24 h from admission. More than half of the GNB were multidrug resistant. The case fatality rate was significantly higher in those with culture positive sepsis.

Sepsis is the third most common cause of neonatal mortality globally. Outborn neonates differ in their microorganisms' profile and antimicrobial resistance (AMR) pattern in comparison to inborn neonates. In this study, we report the microorganisms profile and their AMR pattern in blood culture proven sepsis in a large cohort of outborn (extramural) neonates admitted to the index institute. We have also presented the state-wise profile and have compared their AMR pattern. Out of the 5258 admitted neonates, 3687 blood samples were sent for culture for suspect sepsis. The blood cultures were positive in 537 (14.6%) samples from 514 neonates. Coagulase-negative staphylococcus (CONS) followed by Klebsiella species were the most common organisms isolated from this large cohort of outborn neonates. More than 75% of the neonates grew the organisms within 24 h from admission indicating that many of them harboured the organisms at admission. Case fatality rate was significantly higher in those neonates with culture positive sepsis in comparison to culture negative sepsis. Close to 50% of the gram-negative bacilli isolates were multidrug resistant and half of them were extensively drug resistant. A significant between-state difference in organism profile and their AMR patterns were observed.

Outcome of percutaneous drainage in patients with pancreatic necrosis having organ failure.

BACKGROUND: Percutaneous catheter drainage (PCD) is an effective way of drainage in acute pancreatitis (AP) and its role in persistent organ failure (OF) has not been studied. This study assessed the outcome of severe AP managed with PCD. METHODS: We retrospectively analysed outcome of AP patients undergoing PCD for persistent OF with respect to success of PCD, etiology, severity scores, OF, imaging features and PCD parameters. Success of PCD was defined as resolution of with PCD and survived without surgical necrosectomy. RESULTS: Between January 2016 and May 2018, 83 patients underwent PCD for persistent OF at a mean duration of 25.59 ± 21.2 days from pain onset with successful outcome in 47 (56.6%) patients. Among PCD failures, eleven (13.25%) patients underwent surgery. Overall mortality was 31 (37.3%). On multivariate analysis, pancreatic necrosis <50% and absence of extrapancreatic infection (EPI) predicted the success of PCD. Presence of infected necrosis did not affect the outcome of PCD in organ failure. CONCLUSION: PCD improves the outcome in patients with OF even when done early irrespective of the status of infection of necrosis. Therefore, PCD may be considered early in the course of patients with OF.

Distribution of carbapenemase genes in clinical isolates of Acinetobacter baumannii & a comparison of MALDI-TOF mass spectrometry-based detection of carbapenemase production with other phenotypic methods.

Background & objectives: Carbapenemase-producing Acinetobacter baumannii (CRAB) poses a continuous threat to the current antimicrobial era with its alarming spread in critical care settings. The present study was conducted to evaluate the diagnostic potential of phenotypic methods for carbapenemase [carbapenem-hydrolyzing class D ß-lactamases (CHDLs) and metallo-ß-lactamases (MBLs)] production, by comparing with molecular detection of genes. Methods: One hundred and fifty clinical CRAB isolates collected between August 2013 and January 2014 were studied. Multiplex PCR was performed to identify the carbapenemases produced (class D blaOXA-51, blaOXA-23, blaOXA-48, blaOXA-58; class B blaVIM, blaNDM-1, blaIMP; class A blaKPC). Each isolate was evaluated for carbapenemase production by studying the pattern of imipenem hydrolysis using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Results: The most commonly encountered carbapenemase genes were blaOXA-51(100%), blaOXA-23(98%), blaVIM(49.3%), blaNDM-1(18.7%) and blaOXA-58(2%). MALDI-TOF MS was able to detect 30.6 per cent carbapenemases within three hours (P=0.001 for MBL and P>0.05 for CHDL) and 65.3 per cent within six hours (P=0.001 for MBL and P>0.05 for CHDL). Interpretation & conclusions: MALDI-TOF MS reliably detected carbapenemase activity within a short span of time, thus helping in tailoring patient therapy. MALDI-TOF MS, once optimized, can prove to be a useful tool for timely detection of carbapenemase production by A. baumannii and consequently in directing appropriate antimicrobial therapy.

Antimicrobial susceptibility pattern of Burkholderia cepacia complex & Stenotrophomonas maltophilia from North India: Trend over a decade (2007-2016).

BACKGROUND & OBJECTIVES: With increased isolation of Burkholderia cepacia complex (Bcc) and Stenotrophomonas maltophilia from clinical specimens, knowledge of their antimicrobial susceptibility trend will aid in better patient management. This study provides a comprehensive picture of this trend over a decade. METHODS: A retrospective analysis of laboratory records over 10 years for antimicrobial susceptibility pattern of Bcc and S. maltophilia was carried out. The susceptibility pattern to commonly used antimicrobials was determined using disk diffusion and compared at the beginning, mid and end of the study period. RESULTS: Five hundred and thirty Bcc and 665 S. maltophilia isolated over the past 10 yr were included in the study. Over the years, susceptibility of Bcc for co-trimoxazole varied as 80, 70 and 89 per cent at the beginning, middle and end of the study, respectively. Susceptibility to tetracycline was 43 per cent at the beginning of the study and that to minocycline was 100 per cent mid-study and 74 per cent at the end. Susceptibility to ceftazidime varied as 83, 60 and 65 per cent, respectively, and to meropenem, increased during the first half of the study and decreased in the second half, as 60, 70 and 43 per cent, respectively. Bcc susceptibility to levofloxacin decreased from 84 (in 2014) to 76 per cent (in 2016). S. maltophilia susceptibility to co-trimoxazole varied as 90, 82 and 87 per cent, respectively, whereas that to levofloxacin was 80, 100 and 94 per cent, respectively, during the start, mid and end of the study. Susceptibility to minocycline decreased from 100 per cent mid-study to 96 per cent at the end. Susceptibility of S. maltophilia to ceftazidime increased from 24 (in 2012) to 37 per cent (in 2016). All variations among the three phases of the study were significant for all antimicrobials tested for both the organisms. INTERPRETATION & CONCLUSIONS: While Bcc showed increased resistance to ceftazidime, meropenem and minocycline, S. maltophilia maintained >80 per cent susceptibility to minocycline, levofloxacin and co-trimoxazole throughout the decade. By 2016, Bcc was most susceptible to co-trimoxazole, whereas S. maltophilia was most susceptible to minocycline and levofloxacin.

Examining environmental friendly behaviors of tourists towards sustainable development.

This study investigated the tourists' novel intentions to save environment and what parameters impact their pro-environment decisions. Structural Equation Modeling was used to test the integrated study model to get correct and unbiased path coefficients with the help of 227 responses. The study results revealed that greater the environmental knowledge of environmental friendly products, the more positive attitude towards environmental friendly products was perceived and international tourists perceived it significantly high in comparison to domestic tourists Interestingly Control on Availability didn't impact purchase intentions of tourists in the current study, a finding different from literature across other contexts. Attitude didn't have significant mediating effect in the relationship between environmental knowledge and purchase intentions. On the other hand, purchase intentions positively influenced purchase behavior of tourists. Practical implications are discussed at large.

Antibiotic-resistant Enterobacteriaceae in healthy gut flora: A report from north Indian semiurban community.

Background & objectives: Rampant use of ß-lactam antibiotics in both community and hospitals has transformed the human healthy intestinal gut flora into a reservoir of antibiotic-resistant organisms. This study was conducted to find the faecal presence of antibiotic-resistant Enterobacteriaceae in faecal samples in the community in north India. Methods: In this prospective study, 207 stool samples were collected from apparently healthy individuals residing in a semiurban community in Chandigarh, India, from August to October, 2015. Isolates belonging to family Enterobacteriaceae were identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and antibiotic susceptibility was determined using Clinical Laboratory Standard Institute disc diffusion method. Detection of extended spectrum ß-lactamases (TEM, SHV, OXA-1, CTXM 1, CTXM 2, CTXM 9 and CTXM 8/25), carbapenemases (IMP, VIM and KPC) and New Delhi metallo-ß-lactamase was done by multiplex PCR. Results: Of the population studied, 55.5 per cent were females and 60 per cent were illiterate or had only primary education; 43.4 per cent individuals were aged <20 yr. Overall, 70.5 per cent of stool samples had antibiotic-resistant isolates. Maximum resistance was seen for cephalosporins (60.4%) followed by fluoroquinolones (41.5%). The multidrug-resistant (MDR) isolates were 2.4 per cent. The most commonly detected genes were TEM, SHV, OXA-1, CTXM-1, CTXM-2, CTXM-9 and CTXM-8/25 ß-lactamases. Escherichia coli was the most common resistant isolate, and TEM was the most common gene detected. Interpretation & conclusions: Overall, 70.5 per cent members of Enterobacteriaceae had antibiotic resistance in the community and 2.4 per cent were MDR. Higher resistance rates were observed for most commonly used drugs such as cephalosporins and fluoroquinolones. High rate of antibiotic-resistant Enterobacteriaceae in gut of healthy individuals points towards the need for active screening and prevention of dissemination.

Molecular characterization of extended-spectrum ß-lactamases among clinical isolates of Escherichia coli & Klebsiella pneumoniae: A multi-centric study from tertiary care hospitals in India.

Background & objectives: The increasing prevalence of extended-spectrum ß-lactamases (ESBLs) has abated therapeutic options worldwide. This study was undertaken to investigate the molecular profile and resistance patterns of ESBLs among clinical isolates of Escherichia coli and Klebsiella pneumoniae at four tertiary care centres in India. Methods: Clinical isolates of E. coli and K. pneumoniae were collected from the All India Institute of Medical Sciences (AIIMS), New Delhi; the Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER), Puducherry; Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh and Christian Medical College (CMC), Vellore, over one and a half year period. Antimicrobial susceptibility was determined by Kirby-Bauer disc diffusion method. ESBLs were confirmed phenotypically, and multiplex PCR was performed to identify genes for ß-lactamases (blaTEM, blaSHV, blaOXA-1, blaCTXM-1, blaCTXM-2, blaCTXM-9 and blaCTXM-15). Results: Among 341 E. coli isolates collected during the study period, 171 (50%) harboured blaTEM, 145 (43%) blaOXA-1,70 (21%) blaCTXM-1, 19 (6%) blaSHV and four (1%) harboured blaCTXM-2. Phenotypically, combined disc test detected ESBL production in 98/298 (33%) E. coli. Among 304 K. pneumoniae isolates, 115 (38%), 89 (29%), 83 (27%), 64 (21%) and two (0.6%) harboured blaTEM, blaOXA-1, blaCTXM-1, blaSHV and blaCTXM-2, respectively. Combined disc test (CDT) detected ESBL production in 42 per cent K. pneumoniae. Most of the blaCTXM-1positive isolates were also blaCTXM-15 positive. The carbapenem susceptibility ranged from 56 to 88 per cent for E. coli and from 20 to 61 per cent for K. pneumoniae. Antibiotic sensitivity patterns showed that colistin (CST) was the most sensitive drug for both E. coli (271/274, 99%) and K. pneumoniae (229/234, 98%). Interpretation & conclusions: The prevalence of ESBL among four study centres varied, and blaTEM, blaOXA-1 and blaCTXM-15 were the most common genotypes in E. coli and K. pneumoniae isolates in India. The growing carbapenem resistance and emerging colistin resistance warrant the judicious use of these antimicrobials.

Molecular characterization & epidemiology of carbapenem-resistant Acinetobacter baumannii collected across India.

Background & objectives: Acinetobacter baumannii is an opportunistic pathogen responsible for causing nosocomial infections. A. baumannii develops resistance to various antimicrobial agents including carbapenems, thereby complicating the treatment. This study was performed to characterize the isolates for the presence of various ß-lactamases encoding genes and to type the isolates to compare our clones with the existing international clones across five centres in India. Methods: A total 75 non-repetitive clinical isolates of A. baumannii from five different centres were included in this study. All the isolates were confirmed as A. baumannii by bl aOXA-51-likePCR. Multiplex PCR was performed to identify the presence of extended spectrum ß-lactamases (ESBL) and carbapenemases. Multilocus sequence typing was performed to find the sequence type (ST) of the isolates. e-BURST analysis was done to assign each ST into respective clonal complex. Results: blaOXA-51-likewas present in all the 75 isolates. The predominant Class D carbapenemase was blaOXA-23-likefollowed by Class B carbapenemase, blaNDM-like. Class A carbapenemase was not observed. blaPER-likewas the predominant extended spectrum ß-lactamase. ST-848, ST-451 and ST-195 were the most common STs. Eight-novel STs were identified. e-BURST analysis showed that the 75 A. baumannii isolates were clustered into seven clonal complexes and four singletons, of which, clonal complex 208 was the largest. Interpretation & conclusions: Most of the isolates were grouped under clonal complex 208 which belongs to the international clonal lineage 2. High occurrence of ST-848 carrying blaOXA-23-likegene suggested that ST-848 could be an emerging lineage spreading carbapenem resistance in India.

Pharmacokinetics of colistin in patients with multidrug-resistant Gram-negative infections: A pilot study.

Background & objectives: There is little information concerning intravenously (i.v.) administered colistin in patients with multidrug-resistant (MDR) Gram-negative infections. Thus, this pilot prospective study was undertaken to characterize efficacy and pharmacokinetics of colistin in patients with MDR Gram-negative infections. Methods: Nine patients with age >12 yr and MDR Gram-negative infections were included, of whom six were given colistin at the doses of 2 MU, while three patients were given 1 MU i.v. dose every 8 h. Blood samples were collected at different time intervals. Determination of colistin concentration was done by a ultra-high-performance liquid chromatography/mass spectrometry/selected reaction monitoring assay. Results: The area under the plasma concentration-versus-time curve over eight hours (AUC0-8) for colistin after the 1st dose ranged from 3.3 to 16.4 mg×h/l (median, 4.59). After the 5th dose, AUC0-8for colistin ranged from 4.4 to 15.8 mg×h/l (median, 6.0). With minimal inhibitory concentration (MIC) value of 0.125 mg/l, AUC0-8/MIC ranged from 26.7 to 131.4 (median, 36.7) and 35.5 to 126.0 (median, 48.0) after the 1st and the 5th doses of 2 MU every 8 h, respectively. Interpretation & conclusions: As there is a paucity of information on AUC/MIC for colistin, it may not be possible to conclude whether AUC/MIC values in our patients were adequate. There is a microbiological clearance of organism, which goes in favour of the dosing schedule being adequate. Further studies need to be done to understand the pharmacokinetics of colistin in patients with infections.

Intrapleural streptokinase is effective and safe for children with multi-loculated empyema regardless of the time from disease onset.

AIM: This study compared the efficacy of administering intrapleural streptokinase to children with multi-loculated empyema within 14 days or at any time after disease onset. METHODS: We studied children under 12 years with multi-loculated empyema who were admitted to a teaching hospital in Chandigarh, India, from July 2013 to June 2017. They received antibiotics, pleural drainage and intrapleural streptokinase. The first group received three doses within 14 days of disease onset, the second received three doses regardless of time after onset and the third group received four to six doses regardless of time after onset. The three phases lasted 18, 18 and 12 months, respectively. RESULTS: Of 195 children, 133 (68%) received streptokinase within 14 days, 46 (24%) beyond 14 days and 16 (8%) did not receive it. There was no difference in surgical decortication (14/133 versus 7/46, p > 0.05) and median hospitalisation duration (15 versus 14 days, p > 0.05) between administration before versus after 14 days. Median hospitalisation was shorter with four to six doses than three doses (11 versus 16 days, p < 0.01). CONCLUSION: Intrapleural streptokinase was effective for multi-loculated empyema even when it was administered more than 14 days after disease onset and four to six doses were superior to three doses.

Infection Profile in Chronic Granulomatous Disease: a 23-Year Experience from a Tertiary Care Center in North India.

PURPOSE: Chronic granulomatous disease (CGD) is an inherited phagocytic disorder characterized by recurrent infections with usually catalase-positive organisms. Infections in CGD from developing countries are expected to be different from those in the Western countries. We report the profile of infections in children diagnosed with CGD from a tertiary care center in North India. METHODOLOGY: Case records of children diagnosed with CGD at Pediatric Immunodeficiency Clinic, Advanced Pediatrics Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India, from August 1993 to April 2016 (23 years) were analyzed. RESULTS: Thirty-eight children were diagnosed to have CGD. Median follow-up of patients was 2 years (interquartile range 0.75, 6.0). Staphylococcus aureus and Pseudomonas spp. were the two most common causative bacteria isolated. Aspergillus was the most common fungus isolated. The most common organ involved was the lung (94.7%). Liver abscesses were identified in 5 patients (13.2%), and 20 (52.6%) patients had lymphadenitis. Infections with Pseudomonas spp. were high in our cohort (15.7%) compared to the other studies. Infections with some unusual organisms (e.g., Fusarium dimerium and Chryseobacterium gleum) were also seen in our cohort. Children with X-linked CGD presented earlier and also had a greater number of infections as compared to autosomal recessive CGD. CONCLUSIONS: Various socioeconomic factors coupled with the lack of awareness and paucity of readily available diagnostic facilities for primary immunodeficiencies accounted for a late clinical presentation with severe infections and increased mortality (28.9%) in our cohort. However, mortality was similar in X-linked and autosomal recessive CGD as was the number of fungal infections. The incidence of infections and mortality was significantly lower after initiation of antibacterial and antifungal prophylaxis.

In vitro study of virulence potential of Acinetobacter baumannii outer membrane vesicles.

Acinetobacter baumannii has emerged as an important opportunistic pathogen mostly causing nosocomial infections. The virulence factors of this important pathogen are largely unknown. Outer membrane vesicles (OMV) are naturally secreted by many gram negative and gram positive bacteria. These vesicles contain outer membrane proteins, lipids, periplasmic proteins, DNA and RNA. Their role in intracellular and intercellular signaling, transfer of virulence factors and eliciting immune response in host cells has been established in many pathogens. In this study, we investigated OMVs from three multi-drug resistant (MDR) clinical isolates and a non-MDR reference strain of A. baumannii for virulence potential. A. baumannii OMVs showed phospholipase C, hemolytic and leukotoxic activities. We found large variations in virulence potential between OMVs of MDR clinical isolates and non-MDR reference strain. These effector molecules were concentrated in OMVs than whole cell bacterial culture and cell-free supernatant. OMV-mediated phospholipase, hemolytic and leucotoxic activities may have a key role in pathogenicity of A. baumannii infection and may be future targets for therapeutic and preventive strategies. This is, to the best of our knowledge, the first report showing virulence potential of A. baumannii OMVs.

MALDI-TOF mass spectrometry: An emerging tool for unequivocal identification of non-fermenting Gram-negative bacilli.

BACKGROUND & OBJECTIVES: Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has been instrumental in revolutionizing microbiological identification, especially in high-throughput laboratories. It has enabled the identification of organisms like non-fermenting Gram-negative bacilli (NFGNB), which has been a challenging task using conventional methods alone. In this study an attempt was made to validate MALDI-TOF MS for the identification of clinical isolates of each of the three most common NFGNB, other than Pseudomonas spp., taking molecular methods as the gold standard. METHODS: One hundred and fifty clinical isolates of NFGNB, confirmed by molecular methods such as Acinetobacter baumannii[oxa-51 polymerase chain reaction (PCR)], Burkholderia cepacia complex (expanded multilocus sequence typing) and Stenotrophomonas maltophilia (species-specific PCR), were taken. Isolated colonies from fresh cultures of all 150 isolates were smeared onto ground steel plate, with and without formic acid extraction step. The identification was carried out using MALDI-TOF MS Biotyper database. RESULTS: A concordance of 100 and 73.33 per cent was found between the molecular techniques and MALDI-TOF MS system in the identification of these isolates up to genus and species levels, respectively. Using a cut-off of 1.9 for reliable identification, rate of species identification rose to 82.66 per cent. Principal component analysis dendrogram and cluster analysis further increased discrimination of isolates. INTERPRETATION & CONCLUSIONS: Our findings showed MALDI-TOF MS-based identification of NFGNB as a good, robust method for high-throughput laboratories.

Direct identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) from positive blood culture bottles: An opportunity to customize growth conditions for fastidious organisms causing bloodstream infections.

Culture-negative bacteraemia has been an enigmatic entity with respect to its aetiological agents. In an attempt to actively identify those positive blood cultures that escape isolation and detection on routine workflow, an additional step of MALDI-TOF MS (matrix-assisted laser desorption ionization-time of flight mass spectrometry) based detection was carried out directly from the flagged blood culture bottles. Blood samples from 200 blood culture bottles that beeped positive with automated (BACTEC) system and showed no growth of organism on routine culture media, were subjected to analysis by MALDI-TOF MS. Forty seven of the 200 (23.5%) bacterial aetiology could be established by bottle-based method. Based on these results, growth on culture medium could be achieved for the isolates by providing special growth conditions to the fastidious organisms. Direct identification by MALDI-TOF MS from BACTEC-positive bottles provided an opportunity to isolate those fastidious organisms that failed to grow on routine culture medium by providing them with necessary alterations in growth environment.

Evaluation of evidence for pharmacokinetics-pharmacodynamics-based dose optimization of antimicrobials for treating Gram-negative infections in neonates.

BACKGROUND & OBJECTIVES: Neonates present a special subgroup of population in whom optimization of antimicrobial dosing can be particularly challenging. Gram-negative infections are common in neonates, and inpatient treatment along with critical care is needed for the management of these infections. Dosing recommendations are often extrapolated from evidence generated in older patient populations. This systematic review was done to identify the knowledge gaps in the pharmacokinetics-pharmacodynamics (PK-PD)-based optimized dosing schedule for parenteral antimicrobials for Gram-negative neonatal infections. METHODS: Relevant research questions were identified. An extensive electronic and manual search methodology was used. Potentially eligible articles were screened for eligibility. The relevant data were extracted independently in a pre-specified data extraction form. Pooling of data was planned. RESULTS: Of the 340 records screened, 24 studies were included for data extraction and incorporation in the review [carbapenems - imipenem and meropenem (n=7); aminoglycosides - amikacin and gentamicin (n=9); piperacillin-tazobactam (n=2); quinolones (n=2); third- and fourth-generation cephalosporins (n=4) and colistin nil]. For each of the drug categories, the information for all the questions that the review sought to answer was incomplete. There was a wide variability in the covariates assessed, and pooling of results could not be undertaken. INTERPRETATION & CONCLUSIONS: There is a wide knowledge gap for determining the doses of antimicrobials used for Gram-negative infections in neonates. A different profile of newborns in the developing countries could affect the disposition of antimicrobials for Gram negative infections, necessitating the generation of PK-PD data of antimicrobials in neonates from developing countries. Further, guidelines for treatment of neonatal conditions may incorporate the evidence-based PK-PD-guided dosing regimens.

A meta-analysis to assess usefulness of procalcitonin-guided antibiotic usage for decision making.

BACKGROUND & OBJECTIVES: Development of antibacterial resistance and its association with antibiotic overuse makes it necessary to identify a specific and sensitive biomarker for the diagnosis of bacterial infection and guiding antibiotic therapy. Procalcitonin (PCT), as a sepsis biomarker, may play a role in guiding antibiotics treatment in hospital settings. The aim of the current meta-analysis was to analyze the utility of PCT on various outcomes of interest in inpatients. METHODS: Different databases were searched for randomized controlled trials comparing PCT-guided therapy with standard therapy in admitted patients with bacterial infections. Twenty six articles were found suitable for full text search and of these, 16 studies were considered finally for data extraction. RESULTS: There were no significant differences found in total mortality [pooled odds ratio (OR) 1.04, 95% confidence interval (CI) 0.89-1.22, P=0.63], 28-day mortality (pooled OR 0.97, 95% CI 0.80-1.19, P=0.79), need of Intensive Care Unit admission (OR=0.80, 95% CI 0.59-1.09, P=0.16) and duration of stay in hospital (pooled mean difference -0.01, 95% CI -0.50-0.49, P=0.98) between treatment and control groups. PCT-guided treatment significantly decreased the duration of antibiotic treatment (pooled mean difference -2.79, 95% CI -3.52--2.06, P<0.00001). INTERPRETATION & CONCLUSIONS: PCT-guided therapy significantly decreased antibiotics exposure and thus treatment cost. However, the hard endpoints did not demonstrate any significant benefits, possibly due to low power to detect differences and/or the presence of comorbidities.

Comparison of the efficacy of chlorhexidine gluconate versus povidone iodine as preoperative skin preparation for the prevention of surgical site infections in clean-contaminated upper abdominal surgeries.

PURPOSE: To compare the efficacy of chlorhexidine-gluconate versus povidone iodine in preoperative skin preparation in the prevention of surgical site infections (SSIs) in clean-contaminated upper abdominal surgeries. METHODS: This was a prospective randomized controlled trial conducted on patients undergoing clean-contaminated upper abdominal surgeries. A total of 351 patients 18-70 years old were randomized into two groups; chlorhexidine and povidone iodine skin preparation before surgery. RESULTS: The incidence of SSIs in the chlorhexidine group was 10.8 %, in comparison to 17.9 % in the povidone iodine group. The odds ratio was 0.6 in favor of chlorhexidine use, but the results were not statistically significant (P = 0.06). In the first postoperative week, SSIs developed in 7 % of patients in the chlorhexidine group and 14.1 % in the povidone iodine group (P = 0.03), and in the second postoperative week, SSIs were present in 4.1 % of the patients in the chlorhexidine group and 4.4 % in the povidone iodine group, which was not statistically significant (P = 0.88). CONCLUSIONS: The incidence of SSIs after clean-contaminated upper abdominal surgeries was lower with the use of chlorhexidine skin preparation than with povidone iodine preparation, although the results were not statistically significant. However, the odds ratio between the two groups favored the use of chlorhexidine over povidone iodine for preventing SSIs.