Linezolid resistant coagulase negative staphylococci (LRCoNS) with novel mutations causing blood stream infections (BSI) in India.

BACKGROUND: Coagulase-negative Staphylococci (CoNS) have emerged as a major causative agent of blood-stream infections (BSI). Linezolid (LZD) is currently used for treating glycopeptide and methicillin-resistant staphylococci. It is important to understand the resistance mechanism and probable transmission of LZD resistant (LR) CoNS within the hospital. METHODS: Clinically significant LRCoNS from patients with BSI were characterized using MALDI-TOF and 16S rRNA gene sequence analysis. Antimicrobial susceptibility and MIC of vancomycin and LZD were determined. LZD resistance mechanisms using PCR for the cfr gene and mutation in the V domain of the 23S rRNA gene were studied. RESULTS: The MIC of LZD ranged from 8 to 32 µg/ml. LR was observed in three different CoNS species from diverse locations within the hospital. The cfr gene was identified in all the isolates. Sequence analysis of V domain region of 23S rRNA gene confirmed mutation in single copy among 12/15 isolates with novel mutations: G2614 T and C2384T. All infections were nosocomially acquired and LZD resistance was emerging in the absence of prior LZD use. Horizontal spread of resistant isolates and cfr gene among diverse species were the probable mechanisms of transmission. CONCLUSION: The study highlights the novel mutations associated with LRCoNS and the importance of surveillance & transmission pathway within the hospital. It also systematically discusses the published information on LRCoNS.

Cytomegalovirus infection: its incidence and management in cytomegalovirus-seropositive living related liver transplant recipients: a single-center experience.

It is believed that antiviral prophylaxis decreases the incidence of cytomegalovirus (CMV) reactivation and disease. There are few data regarding weekly assays for CMV DNA after transplantation and the subsequent management of CMV. Here we report a cohort of living related liver transplantation (LRLT) patients who were treated for invasive CMV disease or for CMV infections if they were receiving steroids for rejection. Patients who underwent liver transplantation at our center between September 2006 and August 2010 and were recipient-positive/donor-positive (R(+) /D(+) ) were prospectively included. Patients were tested for CMV DNA 3 weeks after transplantation. CMV DNA-positive patients underwent weekly DNA monitoring until there were 2 consecutive negative reports. Those who developed CMV disease or had rising DNA titers while they were on treatment for rejection were treated. A Cox regression analysis was performed for factors predicting survival. Two hundred sixty-six of the 306 R(+) /D(+) patients were CMV DNA-negative 3 weeks after transplantation, and 40 had detectable DNA. One of the DNA-negative patients developed CMV disease after treatment for rejection with methylprednisolone. Thirty patients had <500 copies/mL, and 10 had ≥500 copies/mL. Two of the 30 patients with DNA levels < 500 copies/mL developed CMV disease. Six of the 10 patients with DNA levels ≥500 copies/mL developed disease. CMV disease occurred in 9 of the 306 patients (2.9%). One patient received treatment for a rise in DNA titers while he was receiving steroids. There was a significant correlation between steroid administration for acute cellular rejection (ACR) and CMV reactivation (P = 0.003) and disease (P = 0.002). A multivariate analysis showed that CMV reactivation/disease did not predict survival. There was no difference in survival between CMV DNA-positive patients and CMV DNA-negative patients (P = 0.68). In conclusion, CMV reactivation is common after LRLT (13%), but the disease is rare (2.9%) without prophylaxis in CMV immunoglobulin G-positive recipients. The administration of steroids for ACR strongly correlates with CMV reactivation and disease. CMV reactivation and disease did not affect survival in our patient cohort.

Fatal pulmonary infection by trimethoprim-sulfamethoxazole resistant Nocardia otitidiscaviarum: report of two cases and review.

INTRODUCTION: Nocardia otitidiscaviarum is a rare cause of human infections, mostly causing cutaneous and lymphocutaneous infections of mild severity. We report two cases of fatal pulmonary infection caused by Nocardia otitidiscaviarum in elderly patients. METHODOLOGY: Case 1: A 70-year old woman presented with fever and cough with expectoration for a month. On physical examination, she had tachypnea and inspiratory crepitations in bilateral basal regions. Case 2: A 74-year old man presented with productive cough with foul smelling expectoration, fever and shortness of breath for one week. On examination, he had tachypnea, bilateral wheezing and inspiratory crepitations. In both cases, sputum was sent to microbiology laboratory. On direct microscopy Gram-positive, finely branching filaments were observed which were acid fast with 1% sulphuric acid. Chalky white opaque wrinkled colonies with musty basement type odour were seen on blood agar. Both patients were treated empirically with trimethoprim-sulfamethoxazole for Nocardia infection after notification of microscopy findings however both expired on Day 2 and Day 5 of admission, respectively. Both isolates were susceptible to amikacin, linezolid, ciprofloxacin and gentamicin. They were resistant to trimethoprim-sulfamethoxazole, ampicillin, amoxicillin-clavulanic acid, erythromycin, and imipenem. Based on biochemical identification and antimicrobial susceptibility pattern, the organism was identified as Nocardia otitidiscaviarum. The identification was confirmed using MALDI-TOF (Vitek MS, Biomerieux, France). CONCLUSION: Our report highlights the importance of early identification of Nocardia to species level to improve treatment outcomes especially in critically ill patients. Mass spectrometry can become an integral part of diagnostic algorithms for nocardiosis.

Anti-drug antibodies and low serum trough infliximab levels correlate with disease activity measures in spondyloarthritis patients on an as-needed infliximab treatment.

AIM: In India, many centers use infliximab at lower doses of 3-5 mg/kg without the loading dose for spondyloarthritis (SpA) patients. It is then continued on an as-required basis, rather than a fixed schedule. Our study was undertaken to see if the trough drug levels and anti-drug antibodies in patients with SpA treated with as-needed infliximab dosing correlated with the disease activity measures. METHODS: Thirty-five adult SpA patients in the age group 18-70 years were recruited. They had received three or more infusions of infliximab at 3-5 mg/kg over the past 6 to 12 months. Patient's serum tumor necrosis factor-α, trough infliximab levels and anti-drug antibodies were measured by enzyme-linked immunosorbent assay technique. The disease activity was quantified by Ankylosing Spondylitis Disease Activity Score - erythrocyte sedimentation rate/ C-reactive protein (ASDAS-ESR/CRP) scores. Correlation between quantitative variables was analyzed by the Spearman's correlation assay. The difference in mean trough infliximab and ASDAS between the drug antibody positive and negative patients was assessed using the Mann-Whitney U test. RESULTS: There was a significant negative correlation between the trough infliximab levels and the ASDAS-ESR (rs = -0.57, P < 0.01) and ASDAS-CRP scores (rs = -0.53, P < 0.01). Anti-drug antibodies were positive in 68.7% of the patients and in comparison to the antibody negative patients, had significantly higher ASDAS-ESR and ASDAS-CRP scores. CONCLUSIONS: Spondyloarthritis patients on low-dose, as-needed infliximab therapy, have both the trough infliximab and anti-drug antibodies correlate significantly with the measures of disease activity. We hypothesize that trough infliximab levels and anti-drug antibodies may be used to predict a suboptimal response due to secondary resistance in SpA patients.

Haemophilus parainfluenzae urethritis through orogenital transmission.

Urethritis, which is characterized by urethral inflammation, results from infectious, traumatic, and immune sources. Amongst the infectious causes, urethritis is usually acquired through sexual route and all show similar symptoms and signs. The present case is from India of a patient with urethritis caused by Haemophilus parainfluenzae transmitted through orogenital route.

Multidrug Resistant Invasive Nontyphoidal Salmonella Isolated from and Masquerading Healed Tubercular Constrictive Pericarditis and Study of Virulence Markers.

Among the infectious causes of pericarditis are various bacteria, viruses, fungal and parasitic infections. The course disease may progress to a chronic constrictive pattern especially with tubercular etiology. Non-typhoidal Salmonella has rarely been reported as a cause of pericarditis. We describe here a case from which the pericardial fluid from an old case of tubercular pericarditis sent for culture to microbiology laboratory grew a Salmonella typhimurium. We studied the antibiotic resistance pattern, phage type and virulence factors playing a role in the invasive nature of the pathogen since no such study from pericardial fluid was found in the literature. The isolate was sensitive only to cephalosporins and it was untypable. It showed amplification for five fimbrial operons, three colonization factors, and other genes (pef operon), gog B(Gifsy-1 encoded effector), sseI (Gifsy-2 encoded effector), sodC ( the periplasmic [copper and zinc Cu, Zn ]-superoxide dismutase) & sopE (a guanine nucleotide exchange factors). The present case highlights the need for early detection of the exact causative agent and serovar in management, the likelihood of a different etiological agent other than the original to be kept in mind for timely management and the highly resistant pattern of non-typhoidal Salmonella (NTS) limiting the therapeutic options as in our case to only cephalosporins. The genes encoded from the NTS might be required for invasive cardiac manifestation in humans.

Characterization of Vancomycin Resistant Enterococci in Hospitalized Patients and Role of Gut Colonization.

INTRODUCTION: Enterococci are part of the normal intestinal flora and have been recognized as important human pathogens. Vancomycin Resistant Enterococci (VRE) are global threat as this resistance is transmissible and also poses a challenge for infection control. AIM: This study was undertaken to study phenotypic and genotypic characteristics of VRE from clinically significant infections among hospitalized patients and their association with gut colonization. MATERIALS AND METHODS: Clinically significant isolates of enterococci (n=250) were studied. Species confirmation was done by Polymerase Chain Reaction (PCR). Minimum Inhibitory Concentration (MIC) for vancomycin was determined by E-test. PCR for VanA, VanB and VanC1 gene was done for genotypic characterization. MIC for teicoplanin, linezolid, tigecycline, daptomycin and quinupristin-dalfopristin was determined by E test. Patients with VRE infection were screened for gut colonization using vancomycin screen agar (6 µg/mL). Continuous data was analysed using the Student's t-test. Categorical data was assessed using Pearson's Chi-square test. A value of p ≤ 0.05 was considered statistically significant. RESULTS: There was good correlation between the phenotypic and genotypic methods used for species identification and detection of vancomycin resistance. E. faecium (162, 64.8%) was most common followed by E. faecalis (82, 32.84%) and E. gallinarum (6, 2.4%). Overall higher resistance was observed among E. faecium. Vancomycin MIC ≥ 2 µg/mL was noted in 63 (25.2%) isolates. Fifty seven isolates showed presence of vanA and vanC1 was detected in six isolates of E. gallinarum. Isolates with VanB genotype was not detected in the present study. MIC50 (µg/mL) for teicoplanin, linezolid, tigecycline, daptomycin and quinupristin-dalfopristrin was 24, 0.75, 0.064, 2 and 0.064 respectively. Resistance to linezolid (1, 1.6%) and tigecycline (2, 3.2%) was rare. Majority (33/47, 70.2%) patients with clinically significant VRE infection showed gut colonization. CONCLUSION: Vancomycin resistance among enterococci is emerging. Emergence of tigecycline and linezolid resistance is also posing a challenge for clinicians. Thus, further investigations are warranted to control vancomycin resistance among pathogens.

Yokenella regensburgei infection in India mimicking enteric fever.

Yokenella regensburgei is an opportunistic human pathogen of the Enterobacteriaceae family rarely reported to cause human infections. Here, we present a case report of Y. regensburgei bacteraemia from India clinically resembling enteric fever in an apparently immunocompetent paediatric patient.