Journal des agents antimicrobiens

Objective: This study aimed to determine the isolates from urine cultures at patients suspected with urinary tract infection and their in-vitro susceptibility pattern to antimicrobials at the Central Laboratory of Research of the “Université Catholique du Graben” (UCG) in Butembo.
Methodology: This was a cross-sectional study adopting a descriptive approach, conducted from January, 2015 to December, 2016. Six hundred and seventeen patients were screened. Freshly voided mid- stream urine sample were taken according to standard method. Isolation of the microbial agents of urinary tract infections was done on blood agar and MacConkey agar media. The culture was repeated in contrast with significant bacteria and urinalysis if the isolate at the first culture is known non-pathogenic. The antimicrobial susceptibility testing was done by using disk diffusion (Kirby Bauer's) technique.
Results: Out of the 617 patients screened, the culture was positive in 77.3% (477 cases). The most isolated bacteria from urine culture were Staphylococcus aureus (47%), Streptococcus spp (12%), Escherischia coli (10.9%), Moraxella spp (7.5%) and Bacillus spp (2.3%). Antibiotics which were sensible to three or more isolates were ciprofloxacin, cefuroxime, cefotaxime and vancomycin. It was also observed that all the bacterial species have a Multiple Antibiotic Resistance Index greater than 0.2.
Conclusion: Continuous monitoring of antimicrobial susceptibility pattern of bacterial isolates implicated in urinary tract infections is needed seeing the high Multiple Antibiotics Resistance Indices of all samples isolates. And this should be prior to antibiotic prescription in order to ensure an optimal, desired and cost-effectiveness treatment. For empiric treatment of urinary tract infections in Butembo, we suggested ciprofloxacin, cefuroxime and cefotaxime as the first line antibiotics of choice.

Background: The emergence of Carbapenemase-producing Enterobacteriaceae (CPE) is a major public health problem worldwide. As Carbapenemase-production has emerged, treatment of infections has become more difficult leading to high mortality. Real time detection of the presence of these enzymes by in vitro susceptibility testing of these organisms is urgently needed to provide effective treatment and appropriate implementation of infection and prevention control measures. Automated phenotypic systems are widely used in clinical microbiology laboratories for bacterial identification and antimicrobial susceptibility testing. However, critical evaluation is needed to determine the accuracy of these systems.
Objective: Our study was set out to evaluate whether the MicroScan® Walkaway system is a reliable method for predicting CPE in patients with a Carbapenem-resistant Enterobacteriaceae (CRE) infections. Methods: This was a cross-sectional study of CRE isolates from July 2015 to July 2016 received as part of an active CRE surveillance programme. Bacterial identification and antimicrobial susceptibility testing for Carbapenems were performed using the MALDI-ToF and MicroScan® Walkaway system, respectively. Genotypic testing was performed using the LightMix® modular Carbapenemase kits in a multiplex real-time PCR assay to confirm the presence of Carbapenemase genes.
Results: During the study period, there were 219 CRE tested. Out of 219 CRE cases, Carbapenemase genes were detected in 173 (78.9%). The most prevalent gene was blaNDM (38.8%; n=85), followed by blaOXA-48 and variants (32.8%; n=72), blaVIM (6.9%; n=15) and blaGES (0.5%; n=1). The MicroScan® Walkaway system had the highest sensitivity with ertapenem (86.7%). Sensitivities for all other Carbapenems were similar, but below 65%. The positive predictive value for ertapenem was 78.9% and >80% for imipenem (86.2%), meropenem (81.3%) and doripenem (83.7%). Overall, testing for all Carbapenems had a sensitivity of 89%, positive predictive value of 79% and specificity of 10.9%, amongst them imipenem having the highest specificity at 60.9%.
Conclusion: The MicroScan® Walkaway system is sensitive, but lacks specificity. However, it shows to be an efficient diagnostic adjunct to the LightMix® modular multiplex real-time PCR assay for predicting CPE in a patient with a CRE infection depending on the Carbapenem used.

Objective: A considerable number of commercially available topical antiseptic solutions rely on free available chlorine as an active ingredient due to its broad-spectrum antimicrobial activity, but limited empirical knowledge exists of the degradation kinetics of chlorine-based solutions in contact with host tissue. To better inform clinical practice, we developed and qualified a rapid and sensitive semi-automated microtiter plate-based iodometric titration assay suitable for the rapid determination of free available chlorine in small samples of dilute antiseptic solutions following contact with biological materials.
Methods: The chlorine determination method described here utilizes a novel stepwise iodometric titration approach performed entirely on a plate reader spectrophotometer equipped with a standard automatic syringe dispenser module. In this method, both titrant addition and colorimetric monitoring steps are carried out automatically, providing significantly higher sample throughput with reduced technical error when compared to the manual titration approach typically used for this type of analysis. Assay qualification was performed by measuring free available chlorine in commercial Dakin’s solution at a range of concentrations during contact with human plasma n vitro and rat muscle tissue in a simulated wound model (ex vivo).
Results: The practical lower limit of quantitation for a 200 μl sample using this assay was found to be approximately 0.001% mass available chlorine and agreement was excellent between measured and nominal percent mass available chlorine over the range concentrations tested. Contact with biological material was found to cause loss of reactive chlorine in Dakin’s solution in seconds to minutes.
Conclusion: The semi-automated available chlorine determination method described here represents numerous improvements to traditional iodometric titration approaches by substantially decreasing required sample volume, drastically increasing throughput, and minimizing manual sample handling and error. We feel this novel method will be of value to other researchers investigating the degradation kinetics of chlorine-based solutions to improve clinical practice.

Hypersaline environments provide an excellent medium for natural microbial communities which serve as a potential source of pharmaceutical substances. Salt is widely present in the earth. Almost 73% of earth was covered with marine water which contains 2.5% of common salt. Protease enzyme activity widespread in microorganisms, plant and animals. Proteolytic enzymes used in the industrial application and bioremediation process. In recent years’ new mutant’s microbe resistant to commonly used antibiotics. Protease inhibitors used as potential antibiotics for controlling microbial infections. A Hypersaline environment such as salt pans and salt lakes has high salt concentration and pH. The saltpan provides a diversity of different environmental conditions of alkalinity, salinity, temperature, pH and nutrition. Halophilic organisms growing between 0.5 and 3.0 M salt concentration. Extreme environments are the best source of bioactive compound producing halophiles microbes.

Objective: The aim of our study was to identify the distribution of Candida species among clinical isolates and their sensitivity pattern for common antifungal drugs.
Methods: This descriptive study was carried out in a tertiary care hospital in Allahabad. A total of One hundred and four Candida isolates were included in the study. Identification and speciation of the isolates were carried out by Germ-tube test, Chlamydoconidia production test, colony characterization in chromogenic agar medium, carbohydrate assimilation test and growth at 45°C. Four antifungal drugs such as Fluconazole (25 mcg), Clotrimazole (10 mcg), Nystatin (100 U) and Amphotericin-B (100 U) were tested by disk diffusion method. Descriptive statistics was used which involves the use of simple percentage and bar chart to analyze the data. In addition, Chi-square test was performed and P value was calculated.
Results: Out of 104 Candida isolates, 60 (58%) were from Urine, 36 (34.5%) were from Sputum and 8(7.5%) were from blood isolates. Of the total of 104 isolates 64 (61.5%) were Candida albicans, 20(19%) Candida dubliniensis, 10 (9%) Candida tropicalis, 7(6.5%) Candida parapsilosis and 4(4%) Candida glabrata respectively. Resistance rates for commonly use antifungal drugs among the isolates are as followed Fluconazole 76 (73%), Amphotericin B 40 (38.5%), Nystatin 4(4%) and Clotrimazole 60 (58%) respectively. For Candida albicans and Candida dubliniensis most active antifungal drug was Nystatin (93%; 100% respectively).
Discussion: Species level identification of Candida and their antifungal sensitivity testing should be performed routinely in all microbiology laboratories to prevent the spread of antifungal resistance.