Systems Biology Approach Predicts Antibody Signature Associated with Brucella melitensis Infection in Humans

A complete understanding of the factors that determine selection of antigens recognized by the humoral immune response following infectious agent challenge is lacking. Here we illustrate a systems biology approach to identify the antibody signature associated with Brucella melitensis (Bm) infection in humans and predict proteomic features of serodiagnostic antigens. By taking advantage of a full proteome microarray expressing previously cloned 1406 and newly cloned 1640 Bm genes, we were able to identify 122 immunodominant antigens and 33 serodiagnostic antigens. The reactive antigens were then classified according to annotated functional features (COGs), computationally predicted features (e.g., subcellular localization, physical properties), and protein expression estimated by mass spectrometry (MS). Enrichment analyses indicated that membrane association and secretion were significant enriching features of the reactive antigens, as were proteins predicted to have a signal peptide, a single transmembrane domain, and outer membrane or periplasmic location. These features accounted for 67% of the serodiagnostic antigens. An overlay of the seroreactive antigen set with proteomic data sets generated by MS identified an additional 24%, suggesting that protein expression in bacteria is an additional determinant in the induction of Brucella-specific antibodies. This analysis indicates that one-third of the proteome contains enriching features that account for 91% of the antigens recognized, and after B. melitensis infection the immune system develops significant antibody titers against 10% of the proteins with these enriching features. This systems biology approach provides an empirical basis for understanding the breadth and specificity of the immune response to B. melitensis and a new framework for comparing the humoral responses against other microorganisms

Bacteriological Profile of Catheter Associated Urinary Tract Infection and its Antimicrobial Susceptibility Pattern in a Tertiary Care Hospital

Introduction: Among nosocomial infections catheter associated urinary infection (CAUTI) is one of the most common infection. Uropathogens isolated from CAUTI are more multi-drug resistant than from community acquired urinary tract infection (UTI). Hence the aim of this study is to isolate uro-pathogens from CAUTI and find out antibiotic sensitivity pattern among the isolates. Material and Methods: This is a prospective and observational study conducted at tertiary care teaching hospital over a period of One year. Urine samples were collected from patients who were catheterized, according to CDC guidelines using sterile needle from tubing of catheter under aseptic precautions. The samples were processed in the Department of Microbiology, as per standard protocols. Uropathogens were isolated, identified and subjected to antibiotic sensitivity testing. Results: The present study shows the pathogens causing CAUTIs and their antibiotic susceptibility pattern. Of 200 urine samples cultured from patients with CAUTI 50 (25%) yielded growth of single organism and 150 (75%) showed no evidence of growth. Escherichia. coli 38% was the predominant pathogen followed by Klebsiella pneumoniae 30%, Pseudomonas aeruginosa 10% Staphylococcus aureus 6.0%. Conclusion: The result showed that the most predominant bacterial isolate causing CAUTI was E. coli. Overall, the percentage of sensitivity of Gram-negative bacteria to all antibiotics tested was relatively low, except for Amikacin, Meropenem and Imipenem which were relatively high. Gram positive cocci showed high susceptibility to Linezolid, Tigecycline and Vancomycin

Serum sICAM, sVCAM and sE-selectin levels in colorectal cancer patients.

Colorectal cancer (CRC) is one of the most common cancers of the gastrointestinal tract and the fourth cause of cancers death in the world. Soluble adhesion molecules (CAMs) are thought to have an important role in host defense against carcinogenesis. They are biomarkers of inflammation and indicators of the immune response to tumors. The study included 40 CRC patients without remote metastases and 24 control subjects. Serum concentrations of sE-selectin, sICAM and sVCAM in patients with CRC were investigated by ELISA method. The level of the sCAMs decreased significantly after radical tumor resection. Preoperative serum concentrations of sICAM and sVCAM in CRC patients were significantly higher compared to the control group, whereas there were no differences regarding serum sE-selectin. Serum levels of sE-selectin, sICAM and sVCAM correlated significantly with each other. There was a significant correlation of serum levels of sICAM-1 and sVCAM-1, but not sE-selectin, with TNM stage and lymph node involvement. No significant relationship was found between serum concentrations of sICAM-1, sVCAM-1 and sE-selectin in CRC patients and patients' age or gender. Our findings suggest that an improved understanding of the mechanisms of membrane shedding of sICAM, sVCAM and sE-selectin is required to delineate their role in tumor progression

A fatal case of empyema thoracis by Nocardia farcinica in an immunocompromised patient

Empyema thoracis by Nocardia farcinica infection is uncommon. Here we report a rare and fatal infection in a 27-year-old HIV- seropositive male who presented with cough, expectoration, and breathlessness. Nocardia farcinica was isolated from sputum and pus from the pleural cavity. Confirmation of the isolate and minimum inhibitory concentrations (MIC) for various antibiotics was done at the Aerobic Actinomycetes Reference Laboratory, Centres for Disease Control and Prevention (CDC), Atlanta. Patient was treated with suitable antibiotics and antiretroviral drugs in spite of which he eventually succumbed to the disease

Antimicrobial susceptibility of Brucella melitensis in Kazakhstan

Abstract Background Kazakhstan belongs to countries with a high level of brucellosis among humans and farm animals. Although antibiotic therapy is the main way to treat acute brucellosis in humans there is still little information on a circulation of the antibiotic-resistant Brucella strains in the Central Eurasia. In this article we describe an occurrence of the drug resistance of Brucella melitensis isolates in Kazakhstan which is among the largest countries of the region. Methods Susceptibilities to tetracyclin, gentamycin, doxycyclin, streptomycin and rifampicin were investigated in 329 clinical isolates of Brucella melitensis using E-test method. Results All isolates were susceptible to streptomycin, tetracycline and doxycycline. 97.3% of the Brucella isolates were susceptible to gentamycin, although only 37.4% of isolates were susceptible to rifampicin. 21.9% of isolates had intermediate resistance, and 26.4% of isolates were resistant to this antibacterial drug. Conclusion Isolates of Brucella melitensis circulating in Kazakhstan are susceptible to streptomycin, doxicyclin, tetracyclin and gentamycin. At the same time the resistance to rifampicin is widespread, almost half of the isolates were rifampicin-resistant (including the intermediate resistance)