ORIGINAL ARTICLE: Detection of β-Lactamase Activity in Various Clinical Bacterial Isolates by Three Different Methods and its Correlation with Drug Resistance.

Background: β-lactams such as penicillins are the most widely used antibiotics, and β-lactamases are the greatest source of resistance to penicillins. Aims and Objectives: To study β-lactamase production in clinical isolates of family Enterobacteriaceae, P. aeruginosa and Staphylococci by three different methods and to correlate its potential with drug resistance; with an endeavour to evaluate convenient and economical method duly supported by relevant Minimum Inhibitory Concentration (MIC) studies. Material and Methods: Total 240 clinical isolates (Gram-negative bacilli-191, staphylococci-49) were subjected to antimicrobial susceptibility testing by Kirby-Bauer disk diffusion method and MIC for ampicillin and penicillin was determined by agar dilution method. β-lactamase was detected by broth acidometric, iodometric cell suspension and microbiological method. Results: Multidrug resistance was observed in more than 90% isolates. One hundred and ninety Gram-negative bacilli were resistant to ampicillin and 47 staphylococcal isolates were resistant to both penicillin and ampicillin. Though microbiological method gave highest positive results 210 (87.5%), iodometric method could detect β-lactamase in apparently sensitive isolates as well giving satisfactory [207 (86.25%)] comparable results. Conclusion: In view of the noted bacterial resistance, tests for β-lactamase should be carried out on a routine basis for an early implementation of appropriate antimicrobial therapy. Iodometric method is eminently convenient, economical and reliable method. Isolates showing MIC <0.125µg/ml for penicillin and MIC <8µg/ml for ampicillin should be checked for β-lactamase production

USE OF CARTRIDGE BASED NUCLEIC ACID AMPLIFICATION TEST FOR RAPID DETECTION OF MYCOBACTERIUM TUBERCULOSIS IN PULMONARY AND EXTRAPULMONARY TUBERCULOSIS

Objective: Tuberculosis is an airborne infection caused by Mycobacterium tuberculosis. Timely diagnosis and treatment are important to prevent the spread of infection. Cartridge-based nucleic acid amplification test&nbsp;(CBNAAT) provides a valuable tool in the early detection of TB. This study is undertaken to evaluate the utility of CBNAAT for the detection of MTB. Comparison of cartridge-based nucleic acid amplification testing with ZN staining. Methods: This prospective observational study was carried out in the Department of Microbiology, BLDEDU’s Shri B. M. Patil Medical College, Hospital and RC and Dr. Karigoudar Diagnostic Laboratory, Vijayapur. A total of 129 samples from patients with the presumptive diagnosis of TB based on history, clinical presentation, and radiological findings were included in the study. All samples were subjected to ZN staining, and Cartridge-based nucleic acid amplification&nbsp;test&nbsp;and data were analyzed. Results: The present study showed ZN smear positivity of 7.75% and CBNAAT positivity of 19.38%. CBNAAT sensitivity and specificity were 90% and 86.55, respectively, compared with ZN staining with a significant P value of &lt;0.001. Conclusion: CBNAAT helps diagnose TB and detect rifampicin resistance within 2-3 h with high sensitivity and specificity. Rifampicin resistance detection is of great concern, which otherwise leads to treatment failure and on time spread of multidrug resistance TB, leading to increased morbidity and mortality

Detection of biofilm among uropathogenic Escherichia coli and its correlation with antibiotic resistance pattern

BACKGROUND: Escherichia coli accounts for 70%–95% of urinary tract infections (UTIs). UTI is a serious health problem with respect to antibiotic resistance and biofilms formation being the prime cause for the antibiotic resistance. Biofilm can restrict the diffusion of substances and binding of antimicrobials. In this context, the present study is aimed to perform in vitro detection of biofilm formation among E. coli strains isolated from urine and to correlate their susceptibility pattern with biofilm formation. MATERIALS AND METHODS: A total of 100 E. coli strains isolated from patients suffering from UTI were included in the study. The identification of E. coli was performed by colony morphology, Gram staining, and standard biochemical tests. The detection of biofilm was carried out by Congo Red Agar (CRA) method, tube method (TM), and tissue culture plate (TCP) method. Antimicrobial sensitivity testing was performed by Kirby–Bauer disc diffusion method on Muller–Hinton agar plate. RESULTS: Of the 100 E. coli strains, 49 (49%) and 51 (51%) were from catheterized and noncatheterized patients, respectively. Biofilm production was positive by CRA, TM, and TCP method were 49 (49%), 55 (55%), and 69 (69%), respectively. Biofilm producers showed maximum resistance to co-trimoxazole (73.9%), gentamicin (94.2%), and imipenem (11.6%) when compared to nonbiofilm producers. Significant association was seen between resistance to antibiotic and biofilm formation with a P = 0.01 (<0.05). CONCLUSION: A greater understanding of biofilm detection in E. coli will help in the development of newer and more effective treatment. The detection of biofilm formation and antibiotic susceptibility pattern helps in choosing the correct antibiotic therapy

Antibiogram of Gram Negative Bacteria Isolated from the Skin and Soft Tissue Infections a Guide for Empirical Therapy to the Clinicians

The antibiogram gives the periodic summary of antimicrobial susceptibilities of local bacterial isolates submitted to the hospitals microbiology laboratory. Antibiogram can be of great use in assessing the local susceptibility rates and can serve as a tool in designing the empirical antibiotic therapy and also in monitoring the resistance trends over time within in an institution. Pus samples from various clinical conditions like abscess, cellulitis, necrotizing fasciitis, wound infections; diabetic foot ulcers were included in the study. A total of 1124 positive cultures were obtained out of which 736 yielded various Gram negative organisms and 488 were Gram positive organisms. Only Gram negative organisms were considered in the study as gram negative organisms are common etiological agents of skin and soft tissue infections and pose a great challenge to the treating physician as they are known to develop a high antimicrobial resistance. The organisms isolated in our hospital were Pseudomonas aeruginosa (192), Klebsiella pneumonia (173), Escherichia coli (168), Citrobacter species (117), Acinetobacter species (47), and Proteus species (39). In our study which aims at formulating an empirical therapy for Gram negative organisms the drugs with highest sensitivity were Imipenem (51%), Amikacin (43%), Meropenem (38%), Tobramycin (36%), and Ciprofloxacin (34%) Gentamicin (34%), Netimicin (33%), Cotrimoxazole (32%), Piperacillin (28%),Tetracycline (28%), Ceftazidime (28%), Levofloxacin (26%), Ceftriaxone (26%), Colistin (22%), Carbenecillin (21%), Cefoperazone (21%), Cefoperazone +Sulbactum (21%), Azonetrem (21%), Cefipime (20%), Cefuroxime (17%), Cephaxlein (15%), Ampicillin (12%), Amoxyclav (10%). With the knowledge of most commonly isolated organisms causing SSTIs and their antimicrobial susceptibility patterns the clinicians can start the most likely antibiotic and can change accordingly once the sensitivity report is available

Comparison of Active and Passive Methods of Air Sampling to Evaluate the Microbial Contamination of Air in Operation Theaters

The microbiological assessment of the air in operating theatres is critical to control hospital-acquired infections. Regular surveillance is an important tool to evaluate the quality of air and find areas requiring intervention. In this context, the present study is undertaken to assess and compare the microbial contamination levels in operation theatre by active and passive methods. All the environmental surfaces and equipment of OTs and ICU at tertiary care hospital in Vijayapur, included in the study. This study used three sampling procedures: active, passive methods for air sampling, and swabing method for surfaces and equipment. Out of 15 OTs air sampling, the passive method showed more bacterial air contamination than the active method. Statistically, a significant difference was observed with the passive method compared to the active method with p-value of 0.0336 for both bacteria and fungus growth assessment. Out of total 90 swabs collected from all the OTs surfaces and instruments, Pseudomonas species (40%), Bacillus species (40%), Klebsiella species (20%) were the common species isolated. From the 50 swabs collected from in ICUs surfaces and instruments, culture positivity was 16% for pathogenic bacteria; Pseudomonas aeruginosa (62%), Klebsiella pneumonia (25%), and Escherichia coli (13%). The present study showed that the passive method is a better monitoring tool than the active method. So we recommend using passive air sampling method compared to active method, which is easy, cheap, and no instrument is needed for sampling the air

A STUDY OF VANCOMYCIN RESISTANT ENTEROCOCCI ISOLATED FROM URINARY TRACT INFECTIONS

Objective: Vancomycin resistant enterococci (VRE) are becoming a major emergence problem concern in urinary tract infection (UTI). This study provides accurate and complete description of antimicrobial susceptibility pattern and to know the prevalence of VRE in this area.Methods: A total of 3400 urine samples were collected and processed bacteriologically. The enterococci was isolated and identified by biochemical tests and Vitek 2. VRE was determined by disc diffusion, agar dilution and Vitek 2 automated machine. Statistical analysis was done by Graph Pad InStat Software.Results: The 143 (4.2%) enterococci were isolated from UTI patients. The incidence was higher in young females and old males. E. faecalis (78%) is the most common isolate followed by E. faecium (15%). The rare species (9%) like E. durans, E. avium, E. gallinarum and E. hirae were also isolated. Fosfomycin (96.5%) and nitrofurantoin (93%) was the drug of choice for enterococcal UTI while linezolid (98.6%) also can be used to treat other enterococcal infections. Among the UTI 98.6% enterococci were susceptible to vancomycin.Conclusion: Empirical therapy for enterococcal infections should be guided by local patterns of drug resistance. Linezolid, fosfomycin or nitrofurantoin may be considered to treat the patients with VRE.Â

Comparative Analysis of Enzyme-Linked Immunosorbent Assay and Immunochromatography for Rotavirus and Adenovirus Detection in Children below Five Years with Acute Gastroenteritis

Introduction The most frequent etiologies of viral gastroenteritis among young children are rotavirus and enteric adenovirus. The clinical signs and symptoms of viral gastroenteritis are not distinct enough to allow for diagnosis. For the diagnosis and treatment of acute gastroenteritis, it is preferable to use quick, simple, and low-cost procedures. This study was undertaken to determine efficacy of immune-chromatography test (ICT) in comparison with enzyme-linked immunosorbent assay (ELISA) to detect rotavirus and adenovirus antigen in fecal specimen among children less than 5 years of age with acute gastroenteritis. Materials and Methods In a cross-sectional observational study, 314 fecal samples were collected from children aged less than 5 years with acute gastroenteritis attending or admitted to a tertiary care hospital during the 1 year study period. Samples were tested for rotavirus and adenovirus antigen using ICT and ELISA. Results Among the 314 children evaluated, 112 (35.66%) had rotavirus infection, nine (2.86%) had adenovirus infection, and three (0.95%) had both rotavirus and adenovirus infection. This study found that ICT is 98.20% sensitive and 100% specific for the diagnosis of rotaviral diarrhea and 100% sensitive and 99.7% specific for adenovirus diarrhea, compared to ELISA. Conclusion Immunochromatography tests used for the detection of rotavirus and adenovirus in the fecal sample showed a high degree of sensitivity and specificity. The ICT is easy to perform and rapid, and it does not require any special equipment. Hence, the ICT could be used as an alternative method for detecting viral pathogens in clinical practice