Plasmid Profile Analysis and bla VIM Gene Detection of Metalo ß-lactamase (MBL) Producing Pseudomonas aeruginosa Isolates from Clinical Samples.

INTRODUCTION: Pseudomonas aeruginosa is a frequent colonizer of hospitalized patients. They are responsible for serious infections such as meningitis, urological infections, septicemia and pneumonia. Carbapenem resistance of Pseudomonas aeruginosa is currently increasingly reported which is often mediated by production of metallo-ß-lactamase (MBL). Multidrug resistant Pseudomonas aeruginosa isolates may involve reduced cell wall permeability, production of chromosomal and plasmid mediated ß lactamases, aminoglycosides modifying enzymes and an active multidrug efflux mechanism. OBJECTIVE: This study is aimed to detect the presence and the nature of plasmids among metallo-ß-lactamase producing Pseudomonas aeruginosa isolates. Also to detect the presence of bla VIM gene from these isolates. MATERIALS AND METHODS: Clinical isolates of Pseudomonas aeruginosa showing the metalo-ß-lactamase enzyme (MBL) production were isolated. The MBL production was confirmed by three different methods. From the MBL producing isolates plasmid extraction was done by alkaline lysis method. Plasmid positive isolates were subjected for blaVIM gene detection by PCR method. RESULTS: Two thousand seventy six clinical samples yielded 316 (15.22%) Pseudomonas aeruginosa isolates, out of which 141 (44.62%) were multidrug resistant. Among them 25 (17.73%) were metallo-ß-lactamase enzyme producers. Plasmids were extracted from 18 out of 25 isolates tested. Five out of 18 isolates were positive for the blaVIM gene detection by the PCR amplification. CONCLUSION: The MBL producers were susceptible to polymyxin /colistin with MIC ranging from 0.5 - 2µg/ml. Molecular detection of specific genes bla VIM were positive among the carbapenem resistant isolates.

A comparative analysis of community acquired and hospital acquired methicillin resistant Staphylococcus aureus.

PURPOSE: Staphylococcus aureus has developed resistance against most of the therapeutic agents. The most notable example of this phenomenon was the emergence of Methicillin resistant Staphylococcus aureus (MRSA). We are reporting the prevalence and the antibiotic susceptibility pattern of the MRSA isolates from a tertiary care hospital. METHODS: A total of 450 Staphylococcus aureus isolates from clinical samples were taken up for the study and they were screened for MRSA by using standard microbiological methods. An antibiotic assay was done for the confirmed MRSA isolates. The differentiation of the isolates into community acquired MRSA (CAMRSA) and hospital acquired MRSA (HAMRSA) was done according to the prescribed criteria. The double disc diffusion test was performed for both the groups, to identify the inducible clindamycin resistance. The HAMRSA and the CAMRSA isolates were subjected to a molecular analysis by PCR, to detect the presence of the Mec A gene and the PVL gene respectively. RESULTS: Out of the 450 Staphylococcus aureus isolates, 121 were Methicillin Resistant Staphylococcus aureus (MRSA, 27%) and 329 were Methicillin Sensitive Staphylococcus aureus (MSSA, 73%). 91 MRSA isolates were grouped into HAMRSA and 30 were grouped into CAMRSA, with a prevalence of 20% and 7% respectively. All the MRSA strains were resistant to Penicillin (100%), Cefoxitin (100%) and Oxacillin (100%). 53.7% of the HAMRSA isolates showed inducible clindamycin resistance against that of 44.4% among the CAMRSA isolates. All the isolates were susceptible to Vancomycin and Linezolid. 64% of the HAMRSA isolates showed the presence of the Mec A gene and 48% of the CAMRSA isolates showed the presence of the PVL genes. CONCLUSION: The prevalence of the HAMRSA was higher than that of the CAMRSA and they showed a higher drug resistance.

The bacteriology of diabetic foot ulcers, with a special reference to multidrug resistant strains.

INTRODUCTION: A diabetic foot infection is one of the most feared complications of Diabetes mellitus. Many studies have reported on the bacteriology of Diabetic Foot Infections (DFIs) over the past 25 years, but the results have been varied and often contradictory. AIMS AND OBJECTIVES: This study was carried out to determine the bacterial profiles of infected ulcers and the antibiotic resistance pattern of the isolates. MATERIALS AND METHODS: Samples were collected from 50 patients with diabetic foot ulcers by using sterile swabs and they were processed. RESULTS: A total of 75 bacterial isolates were obtained from 50 patients with diabetic foot ulcers. The age group of these patients ranged from 35 to 80 years and the maximum number of patients was in the age group of 60 to 65 years. Gram negative bacilli were more prevalent (65.1%) than gram positive cocci (34.9%). The commonest isolate was Pseudomonas spp (16%), followed by Escherichia coli (14.6%) and Staphylococcus aureus (13.3%).The antibiotic sensivity profiles of the bacteria were also studied. 37.5% of the gram negative bacilli were ESBL producers and 31% were carbapenemase producers. CONCLUSION: This study showed a preponderance of gram negative bacilli among the isolates from the diabetic foot ulcers. Knowledge on the antibiotic sensitivity pattern of the isolates will be helpful in determining the drugs for the empirical treatment of diabetic ulcers.

Automated measurement of immature granulocytes: performance characteristics and utility in routine clinical practice.

The granulocytic "shift to left" reflects marrow response to bacterial infection, and this may be quantified as band count or immature granulocyte count (IGC). The former value, used widely in neonatal sepsis, has been notoriously difficult to measure accurately and precisely. A reproducible, precise, and accurate counting of immature granulocyte counts may be possible with automation. This study of 200 febrile patients aimed at analysing the performance characteristics of automated immature granulocytes (AIGs) in predicting blood culture and their clinical utility. The absolute (IGC) and relative IG count (IG%) had area under curve (AUC) of 0.69 and 0.66. Moreover, the means of IGC and IG% between culture positive and negative groups were statistically significant suggesting that they are potential markers for bacteremia. IGC of 0.03 × 10(3) cu·mm and IG% of 0.5% offered sensitivity of 86.3% and 92.2%, respectively, and may be used for screening for bacteremia. Higher values, IGC > 0.3, and IG% > 3 had specificity greater than 90%, although the values were infrequent. It may not be long before that these automated hemograms are put into regular diagnostic use.

The impact of visual layout factors on performance in Web pages: a cross-language study.

Visual layout has a strong impact on performance and is a critical factor in the design of graphical user interfaces (GUIs) and Web pages. Many design guidelines employed in Web page design were inherited from human performance literature and GUI design studies and practices. However, few studies have investigated the more specific patterns of performance with Web pages that may reflect some differences between Web page and GUI design. We investigated interactions among four visual layout factors in Web page design (quantity of links, alignment, grouping indications, and density) in two experiments: one with pages in Hebrew, entailing right-to-left reading, and the other with English pages, entailing left-to-right reading. Some performance patterns (measured by search times and eye movements) were similar between languages. Performance was particularly poor in pages with many links and variable densities, but it improved with the presence of uniform density. Alignment was not shown to be a performance-enhancing factor. The findings are discussed in terms of the similarities and differences in the impact of layout factors between GUIs and Web pages. Actual or potential applications of this research include specific guidelines for Web page design.

Evaluation of a fluorometric method for measuring low concentrations of ammonia in ambient air.

A fluorometric method developed for measuring low concentrations of ammonium in marine and freshwater ecosystems was adapted for the analysis of ammonia in ambient air. The modified method entails collection of samples on an acid-treated solid adsorbent followed by analysis using a fluorometer. Optimal results were obtained using a commercially available sorbent tube containing 100 mg of acid-treated silica gel for sample collection, and an analytical protocol consisting of sample desorption in DI water, addition of orthopthaldialdehyde (OPA) working reagent, and room temperature incubation. Method accuracy and precision were evaluated by comparing experimentally determined quantities of ammonia to expected levels for sample loadings ranging from 0.16 [micro sign]g to 550 [micro sign]g-accuracy was generally within +/-20%. The estimated LOQ for the method is 0.08 [micro sign]g ammonia per sample which represents a 25-375-fold improvement in sensitivity compared to current NIOSH and OSHA methods for the measurement of ammonia in ambient air. The new method should be useful for applications requiring measurement of low concentrations of ammonia using personal sampling equipment or in the characterization of short-term fluctuations of ammonia concentrations in air.