Diving deep for the needle in the haystack: An outbreak investigation of Burkholderia cenocepacia bacteremia.

In an Indian oncology setting, between August and December 2021, 56 patients, developed Burkholderia cenocepacia bacteremia. An investigation revealed a contaminated batch of the antiemetic drug palonosetron. The outbreak was terminated by withdrawing the culprit batch and the findings were reported promptly to regulatory authorities.

Compassionate use of a novel ß-lactam enhancer-based investigational antibiotic cefepime/zidebactam (WCK 5222) for the treatment of extensively-drug-resistant NDM-expressing Pseudomonas aeruginosa infection in an intra-abdominal infection-induced sepsis patient: a case report.

Infections in critically-ill patients caused by extensively-drug-resistant (XDR)-Pseudomonas aeruginosa are challenging to manage due to paucity of effective treatment options. Cefepime/zidebactam, which is currently in global Phase 3 clinical development (Clinical Trials Identifier: NCT04979806, registered on July 28, 2021) is a novel mechanism of action based ß-lactam/ ß-lactam-enhancer combination with a promising activity against a broad-range of Gram-negative pathogens including XDR P. aeruginosa. We present a case report of an intra-abdominal infection-induced sepsis patient infected with XDR P. aeruginosa and successfully treated with cefepime/zidebactam under compassionate use. The 50 year old female patient with past-history of bariatric surgery and recent elective abdominoplasty and liposuction developed secondary pneumonia and failed a prolonged course of polymyxins. The organism repeatedly isolated from the patient was a New-Delhi metallo ß-lactamase-producing XDR P. aeruginosa resistant to ceftazidime/avibactam, imipenem/relebactam and ceftolozane/tazobactam, susceptible only to cefepime/zidebactam. As polymyxins failed to rescue the patient, cefepime/zidebactam was administered under compassionate grounds leading to discharge of patient in stable condition. The present case highlights the prevailing precarious scenario of antimicrobial resistance and the need for novel antibiotics to tackle infections caused by XDR phenotype pathogens.

Determination of potential combination of non-ß-lactam, ß-lactam, and ß-lactamase inhibitors/ß-lactam enhancer against class D oxacillinases producing Acinetobacter baumannii: Evidence from in-vitro, molecular docking and dynamics simulation.

Carbapenem-resistant Acinetobacter baumannii, a predominant nosocomial pathogen in hospitals of intensive care units, is associated with bacteremia and ventilator-associated pneumonia with a high-risk mortality rate. To increase the effectiveness of the ß-lactam (BL) antibiotics, the use of ß-lactamase inhibitors (BLI) acts as a booster when given in combination with BL antibiotics. To this aspect, we selected BL antibiotics of cefiderocol, cefepime, non-BL antibiotic eravacycline, BLI of durlobactam, avibactam, and a ß-lactam enhancer (BLE) of zidebactam. To prove our hypothesis, we determined the minimum inhibitory concentration (MIC) of various BL or non-BL/BLI or BLE combinations using broth microdilution method followed by in silico analysis of molecular docking, molecular dynamics (MD) simulation, and molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) identifies the potential combination. In MIC testing, eravacycline, cefepime/zidebactam, cefiderocol/zidebactam, and eravacycline in combination with zidebactam or durlobactam were found to be effective against oxacillinases (OXAs) (OXA-23/24/58 like) expressing A. baumannii isolates. The docking results of the selected ligands toward OXA-23, OXA-24, and OXA-58 had an excellent binding score ranging from -5.8 to -9.3 kcal/mol. Further, the docked complexes were subjected and evaluated using gromacs for molecular dynamics simulation of 50 ns toward selected class D OXAs. The binding energies obtained from MM-PBSA shed light on the binding efficiencies of each non-BL, BL, and BLI/BLE, thereby helping us to propose the drug combinations. Based on the MD trajectories scoring acquired, we propose using eravacycline, cefepime/zidebactam, cefiderocol/zidebactam, and eravacycline in combination with durlobactam or zidebactam would be promising for treating OXA-23, OXA-24, and OXA-58 like expressing A. baumannii infections.

Lack of Association of Helicobacter pylori in Laryngeal Pathologies.

To study the association of Helicobacter pylori (H. pylori) in patients with laryngeal pathologies. Study design: prospective observational study. Tertiary care teaching hospital. One hundred consecutive patients with laryngeal lesions scheduled for microlaryngoscopy were enrolled in the study. Laryngopharyngeal reflux was assessed using the reflux symptom index and reflux finding score. Tissue samples from the laryngeal lesions were taken under general anaesthesia and were screened for the presence of H. pylori using real time polymerase chain reaction (PCR) for ureA genes and histopathological examination. Of the 100 patients, 14 had a significant reflux symptom index score and 35 had significant reflux finding score. The lesions in the study subjects included both benign and malignant laryngeal pathologies. Vocal cord polyps formed more than half of the laryngeal pathology (57%) studied. Our study could not detect H. pylori in any laryngeal lesions by PCR analysis and histopathological examination. H. pylori may not be associated with laryngeal pathologies.

Hypervirulent Klebsiella pneumoniae infection presenting as endocarditis and liver abscess.

Hypervirulent Klebsiella pneumoniae infection, reported commonly from South-east Asia, is predominantly community-acquired and affects young healthy adults. Although abscesses of liver, brain and muscles, endophthalmitis or osteomyelitis have been reported, Infective endocarditis is a rare manifestation. This report illustrates a patient with uncontrolled diabetes mellitus who presented with clinical features of liver abscess with an incidental finding of infective endocarditis. Hypervirulent K. pneumoniae, which was isolated from blood culture of the patient carried the plasmid borne key virulence markers-rmpA and rmpA2 with enterobactin (entB), type 3 fimbriae (mrkD) and was of K1 type and ST3321, an uncommon clone of Hypervirulent K. pneumoniae. Transthoracic Echocardiography showed multiple mobile vegetations attached to mitral valve and posterior wall of left ventricle. With appropriate antibiotics blood cultures turned sterile, liver abscess and cardiac vegetations reduced in size. Mitral Valve replacement surgery was proposed. He declined treatment and succumbed to the infection subsequently.

Haploidentical transplantation is feasible and associated with reasonable outcomes despite major infective complications-A single center experience from India.

Haploidentical stem cell transplantation (SCT) using post-transplantation cyclophosphamide for graft-versus-host disease (GVHD) prophylaxis is a reasonable therapeutic option for patients who do not have a matched sibling donor. Between 2010 and June 2020, 257 patients underwent 269 Haploidentical transplantations, including 122 children. Indications included both malignant (56.8%) and non-malignant (43.2%) diseases. Conditioning regimens included both myeloablative (57.6%) and nonmyeloablative regimens (42.4%). Peripheral blood stem cells were the predominant graft source (96.2%). Based on the disease risk index, patients were classified into early-, intermediate-, and late-stage disease. Engraftment was seen in 205 patients (76.2%) whereas 39 (14.4%) died before engraftment and 23 (8.6%) had primary graft failure. The cumulative incidence of grade II-IV acute GVHD was 47.8% with a 23.9% incidence of grade III-IV acute GVHD. Chronic GVHD was seen in 41.9% with a 15.4% incidence of extensive chronic GVHD. More than 90% had at least 1 documented infection with a 44% incidence of bacterial, 71% viral, and 38% fungal infection. The 2-year overall survival is 40.5% ± 3.2% with a higher survival among children (48.2% ± 3.4%) compared to adults (34.2% ± 4.1%). Survival was poor with late-stage disease (23.6% ± 4.3%) compared to early- (62.5% ± 7.5%) and intermediate-stage (50.3% ± 4.3%). Factors adversely affecting survival included older age of patient (P = .007), late disease status (P = .000), nonmyeloablative conditioning regimen (P = .003), bone marrow as graft source (P = .006), presence of acute GVHD (P = .069), primary graft failure (P = .000), and presence of a documented bacterial (P = .000) and fungal infection (P = .000). On multivariate analysis, older age (P = .027), presence of acute GVHD (P = .033), documented bacterial infection (P = .000), documented fungal infection (P = .000) and primary graft failure (P = .012) continued to remain significant. Haploidentical SCT offers a reasonable chance of cure for patients with both malignant and nonmalignant hematological diseases. Strategies to reduce aGVHD and infection related mortality needs to be explored further. © 20XX American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

In silico structure evaluation of BAG3 and elucidating its association with bacterial infections through protein-protein and host-pathogen interaction analysis.

BAG3, a co-chaperone protein with a Bcl-2-associated athanogene (BAG) domain, has diverse functionalities in protein-folding, apoptosis, inflammation, and cell cycle regulatory cross-talks. It has been well characterised in cardiac diseases, cancers, and viral pathogenesis. The multiple roles of BAG3 are attributed to its functional regions like BAG, Tryptophan-rich (WW), isoleucine-proline-valine-rich (IPV), and proline-rich (PXXP) domains. However, to study its structural impact on various functions, the experimental 3D structure of BAG3 protein was not available. Hence, the structure was predicted through in silico modelling and validated through computational tools and molecular dynamics simulation studies. To the best of our knowledge, the role of BAG3 in bacterial infections is not explicitly reported. We attempted to study them through an in-silico protein-protein interaction network and host-pathogen interaction analysis. From structure-function relationships, it was identified that the WW and PXXP domains were associated with cellular cytoskeleton rearrangement and adhesion-mediated response, which might be involved in BAG3-related intracellular bacterial proliferation. From functional enrichment analysis, Gene Ontology terms and topological matrices, 18 host proteins and 29 pathogen proteins were identified in the BAG3 interactome pertaining to Legionellosis, Tuberculosis, Salmonellosis, Shigellosis, and Pertussis through differential phosphorylation events associated with serine metabolism. Furthermore, it was evident that direct (MAPK8, MAPK14) and associated (MAPK1, HSPD1, NFKBIA, TLR2, RHOA) interactors of BAG3 could be considered as therapeutic markers to curb down intracellular bacterial propagation in humans.

Stenotrophomonas isolates in a tertiary care centre in South India.

PURPOSE: Stenotrophomonas maltophilia is an emerging multi-drug resistant pathogen increasingly isolated in India. This study aimed to identify patients from whom Stenotrophomonas maltophilia had been isolated and assess predictors of mortality in this population. METHODS: This was a retrospective cohort study of hospitalized patients with a positive culture for S. maltophilia over a 3-year period. Clinical details and laboratory results were assessed from hospital records. Bivariate and multivariate analysis was used to identify risk factors for mortality. RESULTS: One hundred and nineteen patients (mean age 48.6 years) were included in the study. Of these, 111 patients were hospitalized for at least 48 â€‹hours prior to culture and 98 were admitted in the intensive care unit. Bivariate analysis revealed multiple associations with mortality, including a background of renal, cardiac, autoimmune disease, recent carbapenam use and COVID-19 infection and increasing ventilatory requirement, lower PaO2/FiO2 (P/F) ratio, vasopressor use, thrombocytopenia, and hypoalbuminemia at the time of positive isolate. Multivariate analysis showed that autoimmune disease [OR 27.38; 95% CI (1.39-540)], a P/F ratio of less than 300 [OR 7.58; 95% CI (1.52-37.9)], vasopressor requirement [OR 39.50; 95% CI (5.49-284)] and thrombocytopenia [OR 11.5; 95% CI (2.04-65.0)] were statistically significantly associated with increased mortality, while recent surgery and receipt of antibiotics [OR 0.16; 95% CI (0.03-0.8)] targeted against S. maltophilia were associated with decreased mortality. CONCLUSION: Stenotrophomonas maltophilia is primarily isolated in patients in the intensive care unit. In our study the need for vasopressors, autoimmune disease, lower P/F ratios and thrombocytopenia were associated with higher mortality. The association of targeted antibiotics with reduced mortality suggests that the pathogenic role of S. maltophilia should not be underestimated. This finding needs to be confirmed with larger, prospective studies.

Genome sequencing and molecular characterisation of XDR Acinetobacter baumannii reveal complexities in resistance: Novel combination of sulbactam-durlobactam holds promise for therapeutic intervention.

Emerging nosocomial strains of Acinetobacter baumannii are of recent concern as they are expressing extensive drug resistance (XDR). Using whole-genome sequencing and molecular characterisation analysis, the current study reveals the presence of carbapenemase genes in 92.86% of studied Indian isolates. These included blaOXA-51 , blaOXA-23 , blaOXA-58 , and blaNDM genes, with over a third expressing dual carbapenemase genes. As per the MLST scheme, IC2Oxf /CC2Pas was the predominant clone, with 57.14% isolates belonging to this lineage. The presence of these carbapenemase genes resulted in sulbactam (SUL) resistance (MIC: 16-256 µg/ml) in all of the studied isolates. The efficacy of durlobactam (DUR), a novel ß-lactamase inhibitor that also inhibits PBP2 was assessed through in silico intermolecular interaction analysis. Several nonsynonymous single nucleotide polymorphisms were identified in PBP2 (G264S, I108V, S259T) and PBP3 (A515V, T526S) sequences. Minimal variations were recorded in the protein backbone dynamics in active-site motifs of wild-type and mutants, which correlated with negligible binding energy fluctuations for the PBP3-SUL (-5.85 ± 0.04 kcal/mol) and PBP2-DUR (-5.16 ± 0.66 kcal/mol) complexes. Furthermore, higher binding affinities and low inhibition constants were noted in OXA23-DUR (-7.36 kcal/mol; 4.01 µM), OXA58-DUR (-6.44 kcal/mol; 19.07 µM), and NDM-DUR (-6.82 kcal/mol; 10.01 µM) complexes when compared with the conventional drugs avibactam and aztreonam. Stable interaction profiles of DUR with carbapenemases can possibly restore SUL activity against both PBP3WT and PBP3MTs . The study establishes the efficacy of the novel SUL-DUR combination as a successful treatment strategy in combating emerging XDR strains of A. baumannii.

Follow up of a birth cohort to identify prevalence and risk factors for otitis media among Indian children in the eighth year of life.

BACKGROUND: Otitis media, a disease highly prevalent among children worldwide, manifests clinically in both acute and chronic forms. The manner and time at which chronicity develops among Indian children is unknown. AIM: To study the prevalence, manifestations and risk factors for otitis media in a birth cohort aged 8 years. METHODS: A birth cohort of 107 babies was followed up at 8 years of age and ENT evaluation with nasopharyngeal swabbing for detecting Streptococcus pneumoniae and Hemophilus influenzae was performed. RESULTS: The overall prevalence of otitis media was 14%, almost half the prevalence in the first 2 years of life. Eight children (7.5%) with congested, bulging eardrums and no systemic symptoms had asymptomatic acute otitis media. Another five (4.7%) children had otitis media with effusion and 2 (1.9%) had chronic suppurative otitis media. Although 10/15 (66.7%) children with otitis media had positive swabs at 8 years age, only 2 were pneumococcal vaccine (PCV-13) serotypes. Risk factor analysis showed that passive smoking was the only significant parameter associated with otitis media (p = 0.029). Nasopharyngeal swabbing showed that 51/105 (48.6%) children had positive swabs for S. pneumoniae and 5/105 (4.8%) for S.pneumoniae with non-type b H. influenzae. The ten most commonly encountered pneumococcal serotypes were 6A,4,8,16F,33B,35A,35B, 18C, 19F and 23B which together comprised 29 of the 56 (51.8%) isolates. PCV-13 serotypes formed 19/56 (33.9%) to 21/56 (37.5%) of all pneumococcal isolates. Of 6 children who had received PCV-13, 4 tested positive for S. pneumoniae at 8 years of age too. However, none were vaccine serotypes. Four of those with otitis media who had positive swabs had received no immunisation at all and 3 of them had vaccine serotypes, viz. 4, 6A and 18C respectively. CONCLUSION: Indian children continue to have a high prevalence of otitis media at 8 years age. More than 1/3 of nasopharyngeal isolates at this age are vaccine serotypes. Passive smoking is an important risk factor for childhood otitis media and may contribute to the development of chronicity of the disease.

Burden of diabetes among patients with tuberculosis: 10-year experience from a tertiary care referral teaching hospital in South India.

CONTEXT: Tuberculosis (TB) and diabetes mellitus (DM) are converging epidemics, each worsening the morbidity of the other. A study of the prevalence of DM in TB patients assumes great importance. AIMS: The study aims to evaluate the association between DM and TB over a 10-year period in a tertiary care hospital. SETTINGS AND DESIGN: A retrospective observational study in a southern Indian tertiary care teaching hospital was conducted. MATERIALS AND METHODS: All patients with TB diagnosed and treated during the 10-year study period were identified from the hospital database. All relevant clinical, microbiological, and laboratory results pertaining to diagnosis of DM were collected. The diagnosis of TB and DM was made as per the standard criteria. STATISTICAL ANALYSIS: Categorical variables were analyzed using Chi-square test while continuous variables using independent sample t-test. RESULTS: From 2001 to 2012, we studied 1979 TB patients among whom data on DM were available. The prevalence of DM was 29%, 21%, and 14%, in smear positive, smear negative and extrapulmonary TB respectively (overall 24%). Diabetics were more likely to be men (77.3% vs. 61%;P = 0.001); >40 years of age (81.7% vs. 38.9%;P < 0.001); heavier (59.96 vs. 50.37;P = 0.004); tobacco smokers (16.1% vs. 8.1%;P < 0.001); and alcohol consumers (6.8% vs. 4%;P = 0.02). They were less likely to be HIV coinfected (1.8% vs. 6.1%;P < 0.001). HIV coinfection was seen in 5% of patients and was substantially higher in extrapulmonary TB group (19.4%). Multidrug-resistant TB was lower in DM (11.7%) compared to non-DM (15.9%) (P = 0.02). Overall, 48% of the DM patients were diagnosed at the time of TB diagnosis. Over 10 years, no obvious changes in the trend were evident. CONCLUSIONS: Over a 10-year study period, 24% of the TB patients were diabetic, nearly half were detected at the time of TB diagnosis. There may be a good case for screening all TB patients for DM.

Drug-resistant organisms are common in fecal surveillance cultures, predict bacteremia and correlate with poorer outcomes in patients undergoing allogeneic stem cell transplants.

BACKGROUND: With the increasing incidence of multidrug-resistant (MDR) organisms and high mortality rates associated with these infections, we describe the spectrum of the major drug-resistant pathogens identified in fecal surveillance, and re-visit the use of fecal surveillance in predicting infection with these organisms post-allogeneic stem cell transplant. METHODS: Data from allogeneic stem cell transplant recipients with common drug-resistant strains of bacteria in fecal surveillance (Escherichia coli, Klebsiella spp., and Enterococcus spp.) were compared with recipients who did not have the same in fecal surveillance cultures. Baseline characteristics and post-transplant outcomes including similar drug resistance in blood cultures, severe sepsis, and 100-day transplant-related mortality were compared. Multivariate analysis using logistic regression model was used to determine independent predictors of outcome. RESULTS: In 232 transplants, the prevalence of common drug-resistant isolates in fecal surveillance cultures was 57.7% (134 out of 232 patients-with a single isolate in 115 and ≥2 isolates in the remaining 19 patients. A total of 164 drug-resistant isolates were obtained from 134 patients. Of the 164 isolates, 133 (81%) were positive for ESBL screening, 19 (11.5%) for carbapenem-resistant organisms (CRO) screening, 12 (7.3%) for VRE screening. Patients who had common drug-resistant pathogens detected in fecal surveillance have significantly higher subsequent blood culture positivity with drug resistance, as well as higher 100-day mortality. Factors influencing 100-day mortality included patient's age (P = .001), drug resistance positivity in blood (P < .001), drug resistance in fecal surveillance (P = .011), use of an alternate donor (other than fully matched sibling) (P < .001), GVHD grade 3-4 (P < .001), and severe sepsis (P < .001). On multivariate analysis, only use of an alternate donor (0.024), severe sepsis (P < .001), and grade 3-4 GVHD (P < .001) retained significance in predicting 100-day mortality. CONCLUSION: Organisms resistant to 3rd generation cephalosporins are frequently seen on fecal surveillance in the pre-transplant setting and are associated with a higher incidence of drug-resistant organisms in subsequent blood cultures (not limited to the same drug resistance pattern as seen in fecal surveillance). Drug-resistant organisms in fecal surveillance are associated with poorer outcomes following allogeneic stem cell transplant and may be used as a guide to identify patients at risk of subsequently developing a drug-resistant organism in blood.

Genomic insights on heterogeneous resistance to vancomycin and teicoplanin in Methicillin-resistant Staphylococcus aureus: A first report from South India.

Methicillin-resistant Staphylococcus aureus (MRSA) infection is an important clinical concern in patients, and is often associated with significant disease burden and metastatic infections. There is an increasing evidence of heterogeneous vancomycin-intermediate S. aureus (hVISA) associated treatment failure. In this study, we aim to understand the molecular mechanism of teicoplanin resistant MRSA (TR-MRSA) and hVISA. A total of 482 MRSA isolates were investigated for these phenotypes. Of the tested isolates, 1% were identified as TR-MRSA, and 12% identified as hVISA. A highly diverse amino acid substitution was observed in tcaRAB, vraSR, and graSR genes in TR-MRSA and hVISA strains. Interestingly, 65% of hVISA strains had a D148Q mutation in the graR gene. However, none of the markers were reliable in differentiating hVISA from TR-MRSA. Significant pbp2 upregulation was noted in three TR-MRSA strains, which had teicoplanin MICs of 16 or 32 µg/ml, whilst significant pbp4 downregulation was not noted in these strains. In our study, multiple mutations were identified in the candidate genes, suggesting a complex evolutionary pathway involved in the development of TR-MRSA and hVISA strains.

Plasmid profiles among some ESKAPE pathogens in a tertiary care centre in south India.

Background & objectives: Plasmid has led to increase in resistant bacterial pathogens through the exchange of antimicrobial resistance (AMR) genetic determinants through horizontal gene transfer. Baseline data on the occurrence of plasmids carrying AMR genes are lacking in India. This study was aimed to identify the plasmids associated with AMR genetic determinants in ESKAPE pathogens. Methods: A total of 112 ESKAPE isolates including Escherichia coli (n=37), Klebsiella pneumoniae (n=48, including 7 pan-drug susceptible isolates), Acinetobacter baumannii (n=8), Pseudomonas aeruginosa (n=1) and Staphylococcus aureus (n=18) were analyzed in the study. Isolates were screened for antimicrobial susceptibility and whole genome sequencing of isolates was performed using Ion Torrent (PGM) sequencer. Downstream data analysis was done using PATRIC, ResFinder, PlasmidFinder and MLSTFinder databases. All 88 whole genome sequences (WGS) were deposited at GenBank. Results: Most of the study isolates showed resistant phenotypes. As analyzed from WGS, the isolates included both known and unknown sequence types. The plasmid analysis revealed the presence of single or multiple plasmids in the isolates. Plasmid types such as IncHI1B(pNDM-MAR), IncFII(pRSB107), IncFIB(Mar), IncFIB(pQil), IncFIA, IncFII(K), IncR, ColKP3 and ColpVC were present in K. pneumoniae. In E. coli, IncFIA, IncFII, IncFIB, Col(BS512), IncL1, IncX3 and IncH were present along with other types. S. aureus harboured seven different plasmid groups pMW2 (rep 5), pSAS1 (rep 7), pDLK1 (rep 10), pUB110 (rep US12), Saa6159 (rep 16), pKH12 (rep 21) and pSA1308 (rep 21). The overall incidence of IncF type plasmids was 56.5 per cent followed by Col type plasmids 18.3 per cent and IncX 5.3 per cent. Other plasmid types identified were <5 per cent. Interpretation & conclusions: Results from the study may serve as a baseline data for the occurrence of AMR genes and plasmids in India. Information on the association between phenotypic and genotypic expression of AMR was deciphered from the data. Further studies on the mechanism of antibiotic resistance dissemination are essential for enhancing clinical lifetime of antibiotics.

Evaluation of risk factors for colistin resistance among uropathogenic isolates of Escherichia coli and Klebsiella pneumoniae: a case-control study.

INTRODUCTION: The last few years have seen the emergence of multi-drug resistant (MDR) Gram-negative infections, which are associated with high morbidity and mortality. The indiscriminate use of colistin has led to the development of resistance, which can be diagnosed effectively by broth microdilution. Studies from India are limited, and this study was conducted in order to determine the prevalence and risk factors associated with colistin resistance. METHODS: Urine samples from patients admitted with urinary tract infection (UTI), growing MDR Escherichia coli and Klebsiella pneumoniae, were tested for the minimum inhibitory concentration (MIC) of colistin by broth microdilution. Isolates with an MIC >2 µg ml-1 (resistant) were subjected to polymerase chain reaction (PCR) for the mcr1, mcr2 and mgrB genes. A case-control study with 21 cases (resistant) and 42 matched controls (sensitive) was designed to evaluate risk factors and outcomes (recurrent UTI, readmission and hospital stay >2 weeks). RESULTS: Two hundred and fifty MDR isolates (E. coli=142/2319 and K.pneumoniae=108/775) from 216 patients were selected from the 25 046 isolates screened. Twenty-five isolates (20 K.pneumoniae and 5 E. coli) were resistant to colistin, with a prevalence of 3.52  % in E. coli and 18.5  % in K. pneumoniae among the MDR isolates. PCR for the mcr1 and mcr2 genes was negative. Multivariate regression showed that multiple episodes of hospitalization, hospital stay >2 weeks, exposure to >three antibiotic classes and abnormality/surgery of the lower urinary tract were the significant risk factors for colistin resistance. Previous use of colistin and colistin resistance had a significant effect on all outcomes. CONCLUSIONS: K. pneumoniae show six times higher prevalence of colistin resistance than E. coli, and the emergence of resistant organisms has led to an increase in morbidity in infected patients.

Accurate identification and epidemiological characterization of Burkholderia cepacia complex: an update.

Bacteria belonging to the Burkholderia cepacia complex (Bcc) are among the most important pathogens isolated from cystic fibrosis (CF) patients and in hospital acquired infections (HAI). Accurate identification of Bcc is questionable by conventional biochemical methods. Clonal typing of Burkholderia is also limited due to the problem with identification. Phenotypic identification methods such as VITEK2, protein signature identification methods like VITEK MS, Bruker Biotyper, and molecular targets such as 16S rRNA, recA, hisA and rpsU were reported with varying level of discrimination to identify Bcc. rpsU and/or 16S rRNA sequencing, VITEK2, VITEK MS and Bruker Biotyper could discriminate between Burkholderia spp. and non-Burkholderia spp. Whereas, Bcc complex level identification can be given by VITEK MS, Bruker Biotyper, and 16S rRNA/rpsU/recA/hisA sequencing. For species level identification within Bcc hisA or recA sequencing are reliable. Identification of Bcc is indispensable in CF patients and HAI to ensure appropriate antimicrobial therapy.

A comparative assessment of clinical, pharmacological and antimicrobial profile of novel anti-methicillin-resistant Staphylococcus aureus agent levonadifloxacin: Therapeutic role in nosocomial and community infections.

Staphylococcus aureus is of significant clinical concern in both community- and hospital-onset infections. The key to the success of S. aureus as a pathogen is its ability to swiftly develop antimicrobial resistance. Methicillin-resistant S. aureus (MRSA) is not only resistant to nearly all beta-lactams but also demonstrates resistance to several classes of antibiotics. A high prevalence of MRSA is seen across worldwide. For many decades, vancomycin remained as gold standard antibiotic for the treatment of MRSA infections. In the past decades, linezolid, daptomycin, ceftaroline and telavancin received regulatory approval for the treatment of infections caused by resistant Gram-positive pathogens. Although these drugs may offer some advantages over vancomycin, they also have significant limitations. These includes vancomycin's slow bactericidal activity, poor lung penetration and nephrotxicity;linezolid therapy induced myelosuppression and high cost of daptomycin greatly limits their clinical use. Moreover, daptomycin also gets inactivated by lung naturally occurring surfactants. Thus, currently available therapeutic options are unable to provide safe and efficacious treatment for those patients suffering from hospital-acquired pneumonia, bloodstream infections (BSIs), bone and joint infections and diabetic foot infections (DFI). An unmet need also exists for a safe and efficacious oral option for switch-over convenience and community treatment. Herein, the review is intended to describe the supporting role of anti-staphylococcal antibiotics used in the management of S. aureus infections with a special reference to levonadifloxacin. Levonadifloxacin and its prodrug alalevonadifloxacin are novel benzoquinolizine subclass of quinolone with broad-spectrum of anti-MRSA activity. It has been recently approved for the treatment of complicated skin and soft-tissue infection as well as concurrent bacteraemia and DFI in India.

Genomic insights of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) with reduced teicoplanin susceptibility: A case of fatal necrotizing fasciitis.

OBJECTIVES: Glycopeptides are increasingly being used to treat multiresistant methicillin-resistant Staphylococcus aureus (MRSA) infections. Here we report an MRSA isolate with low-level teicoplanin resistance (isolate VB26276) recovered from a patient treated with teicoplanin for fatal necrotizing fasciitis. METHODS: Minimum inhibitory concentrations (MICs) of MRSA isolates to vancomycin and teicoplanin were determined by Etest. Reduced glycopeptide susceptibility was screened by Etest GRD (glycopeptide resistance detection) and population analysis profile (PAP) method. Next-generation sequencing (NGS) was also performed to determine the molecular mechanism of antimicrobial resistance and virulence. RESULTS: The teicoplanin MIC of MRSA isolate VB26276 was 4µg/mL. NGS showed the presence of mutations in the tcaA and tcaB genes of the tcaRAB operon that determines the level of teicoplanin resistance. In addition, a mutation in the vraR gene was found to be associated with teicoplanin resistance, but not with vancomycin heteroresistance. CONCLUSION: Teicoplanin resistance may occur due to point mutations in the teicoplanin resistance operon tcaRAB. Further studies are warranted to determine the contribution of point mutations in tcaRAB to reduced teicoplanin susceptibility.

Polymyxin susceptibility testing, interpretative breakpoints and resistance mechanisms: An update.

Emerging multidrug-resistant (MDR) nosocomial pathogens are a great threat. Polymyxins, an old class of cationic polypeptide antibiotic, are considered as last-resort drugs in treating infections caused by MDR Gram-negative bacteria. Increased use of polymyxins in treating critically ill patients necessitates routine polymyxin susceptibility testing. However, susceptibility testing both of colistin and polymyxin B (PMB) is challenging. In this review, currently available susceptibility testing methods are briefly discussed. The multicomponent composition of colistin and PMB significantly influences susceptibility testing. In addition, poor diffusion in the agar medium, adsorption to microtitre plates and the synergistic effect of the surfactant polysorbate 80 with polymyxins have a great impact on the performance of susceptibility testing methods This review also describes recently identified chromosomal resistance mechanisms, including modification of lipopolysaccharide (LPS) with 4-amino-4-deoxy-l-arabinose (L-Ara4-N) and phosphoethanolamine (pEtN) resulting in alteration of the negative charge, as well as the plasmid-mediated colistin resistance determinants mcr-1, mcr-1.2, mcr-2 and mcr-3.

Clinical Outcomes in Musculoskeletal Involvement of Burkholderia Pseudomallei Infection.

BACKGROUND: Musculoskeletal involvement in melioidosis is often seen in conjunction with a disseminated illness. Recent reports suggest that operative management of musculoskeletal melioidosis has favourable results. The purpose of this study was to review the patient profile and clinical outcomes of Burkholderia pseudomallei infection in the musculoskeletal system. METHODS: Hospital records of 163 patients who were diagnosed to have B. pseudomallei infection between January 2009 and December 2014 were reviewed. Patients underwent surgical and nonsurgical management depending upon the tissue of involvement. Epidata software was used to record the data. The SPSS ver. 17.0 was used for analysis. RESULTS: Eighteen out of 24 patients who had musculoskeletal melioidosis were available for follow-up. Septic arthritis, osteomyelitis, and intramuscular abscess were the common diagnosis, with 6 patients in each group. Twelve patients required surgical intervention. All patients received a full course of parenteral ceftazidime followed by oral doxycycline and co-trimoxazole. Two out of 6 patients (33.3%) died among those who had nonsurgical management as compared to none in the group who had surgical management. This was significant at 10% level of significance (p = 0.098). The rest were followed up for a minimum of 1 year with no evidence of disease recurrence. CONCLUSIONS: This series describing musculoskeletal involvement in melioidosis is the largest such study from a recently recognized 'endemic' region. Of importance are the patterns of musculoskeletal involvement, pitfalls in diagnosis and adequate clinical response with timely diagnosis and appropriate surgical management.