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Microbiological Characteristics (microbiological + characteristic)
Selected AbstractsMicrobiological characteristics of clinical isolates of Cryptococcus neoformans in Taiwan: serotypes, mating types, molecular types, virulence factors, and antifungal susceptibilityCLINICAL MICROBIOLOGY AND INFECTION, Issue 6 2010S-J. Liaw Clin Microbiol Infect 2010; 16: 696,703 Abstract This study investigated the microbiological characteristics of 100 clinical isolates of Cryptococcus neoformans species complex, including serotypes, mating types, molecular types, antifungal susceptibility and virulence. The isolates were collected at National Taiwan University Hospital from 1999 to 2004. Eight isolates of C. neoformans from pigeon droppings were also evaluated. Among these isolates, 99 were C. neoformans var. grubii serotype A and one was C. neoformans var. gattii serotype B. All of these isolates were , mating types. PCR fingerprinting, generated by primers M13 and (GACA)4, and URA5 gene restriction fragment length polymorphism analysis revealed that C. neoformans var. grubii isolates belonged to the VNI (98 isolates) and the VNII (one isolate) types, and the single C. neoformans var. gattii was VGI type. The similar profiles of clinical and environmental isolates suggest that patients might acquire these yeasts from the environment. The MIC90 for fluconazole, itraconazole, 5-flucytosine, voriconazole and amphotericin B against all C. neoformans isolates were 8, 0.5, 4, 0.125 and 0.5 mg/L, respectively. All clinical isolates produced urease, phospholipase, capsule and melanin, but these activities varied with individual isolates. Analysis of six clinical and two environmental isolates with various levels of phospholipase activity indicated a correlation between phospholipase activity and the ability to adhere to the lung epithelial cell line, A549. The extent of cell damage, as indicated by lactate dehydrogenase release, also paralleled the phospholipase activity of these isolates. In addition, production of melanin contributed significant protection against amphotericin B killing of the isolates tested. [source] A comparison of the physicochemical, microbiological and aromatic composition of Traditional and Industrial Leben in TunisiaINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 1 2010OLFA SAMET-BALI Traditional Tunisian Leben (TL) was produced according to the traditional method. Physicochemical and microbiological characteristics and major aromatic compounds were studied and compared to industrial Leben (IL) and experimental Leben (EL). The results show a decrease in lactose content and pH value and an increase in lactic acid during spontaneous fermentation. TL and EL were characterised by higher protein, lactose and ash contents but were less fatty and acidic than IL. Lactic acid bacteria (LAB) and yeasts present in TL were responsible for lactic acid fermentation and aroma development. The LAB and yeast counts in TL were higher than that in EL and IL. Dynamic headspace extraction procedure shows the existence of four major volatile compounds: acetaldehyde, ethanol, diacetyl and acetoin in TL, IL and EL. However, TL has the most important quantity of aroma. [source] Chemical and microbiological quality of Garris, Sudanese fermented camel's milk productINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2006Abdel Moneim El-Hadi Sulieman Summary In the present study, some of the chemical and microbiological characteristics of garris, a Sudanese traditionally fermented camel's milk product, were investigated. The chemical analyses included, pH, titrable acidity and ethanol contents. A total of 100 strains of lactic acid bacteria (LAB) were isolated from twenty samples of traditionally fermented household garris. The selected isolates were phenotypically characterized by their ability to ferment 49 carbohydrates using API 50 CHL kits and additional biochemical tests. LAB dominated the microflora of garris samples, and the major genera were Lactobacillus (74%), followed by Lactococcus (12%), Enterococcus (10%) and Leuconostocs (4%). The most predominant Lactobacillus species were identified as Lactobacillus paracasei ssp. paracasei (64 strains), L. fermentum (seven strains) and only three strains as L. plantarum. Most strains produced the enzymes that are relevant to cultured dairy product processing. The Lactococcus species were identified as Lactococcus lactis. The average pH value of the samples was 4.42 ± 0.21. The pH values were accompanied with increasing of titrable acidity which averaged 1.72 ± 0.04%. The relatively high amounts of ethanol detected in all samples (average 1.40 ± 0.03%) together with the high yeasts counts (6.0 ± 0.53 log10 cfu mL,1), indicated that the fermentation process of garris is a yeast-lactic fermentation. [source] Effect of Modified Atmosphere Packaging and Soluble Gas Stabilization on the Shelf Life of Skinless Chicken Breast FilletsJOURNAL OF FOOD SCIENCE, Issue 2 2006Bjørn T. Rotabakk ABSTRACT The suitability of soluble gas stabilization (SGS) to dissolve CO2 into skinless chicken breast fillets before modified atmosphere (MA) packaging (MAP) was investigated. Head space gas composition (%), top web deflation (mm), muscle surface color (Minolta L*a*b*), pH, exudates in the packages (%), microbial characteristics, and off-odor were assessed in the packaged fillets. Increased SGS treatment time (2 versus 12 h) before MA packaging increased the CO2 content in the packaged fillets and counteracted package collapse. High package filling degree (51.8%) (low gas to product volume ratio) gave significantly (P < 0.001) lower CO2 content in head space than normal filling degree (29.7%). Color, pH, and package exudates were not affected by SGS treatment. Aerobic plate count (APC), Enterbacteriaceae count (EC), and lactic acid bacteria (LAB) increased significantly (P < 0.001) at each sampling during storage (5, 11, 17, and 24 d). SGS treatment significantly (P < 0.015) decreased APC, EC, and Pseudomonas spp. counts (PC) compared with no SGS treatment. Filling degree did not have a significant effect on the investigated microbiological characteristics. Off-odor scores correlated highest with EC (r2(adj)= 0.82). Fillets SGS treated in 12 h were the only one not rejected at off-odor evaluation on day 24. The samples stored in air spoiled after 5 d. SGS treatment in combination with MAP can be used successfully on chicken breast fillets to improve the microbiological (APC, EC, and PC) and sensorial characteristics, and in addition reduce package collapse and possibly increase the filling degree. [source] Microbiological characteristics of clinical isolates of Cryptococcus neoformans in Taiwan: serotypes, mating types, molecular types, virulence factors, and antifungal susceptibilityCLINICAL MICROBIOLOGY AND INFECTION, Issue 6 2010S-J. Liaw Clin Microbiol Infect 2010; 16: 696,703 Abstract This study investigated the microbiological characteristics of 100 clinical isolates of Cryptococcus neoformans species complex, including serotypes, mating types, molecular types, antifungal susceptibility and virulence. The isolates were collected at National Taiwan University Hospital from 1999 to 2004. Eight isolates of C. neoformans from pigeon droppings were also evaluated. Among these isolates, 99 were C. neoformans var. grubii serotype A and one was C. neoformans var. gattii serotype B. All of these isolates were , mating types. PCR fingerprinting, generated by primers M13 and (GACA)4, and URA5 gene restriction fragment length polymorphism analysis revealed that C. neoformans var. grubii isolates belonged to the VNI (98 isolates) and the VNII (one isolate) types, and the single C. neoformans var. gattii was VGI type. The similar profiles of clinical and environmental isolates suggest that patients might acquire these yeasts from the environment. The MIC90 for fluconazole, itraconazole, 5-flucytosine, voriconazole and amphotericin B against all C. neoformans isolates were 8, 0.5, 4, 0.125 and 0.5 mg/L, respectively. All clinical isolates produced urease, phospholipase, capsule and melanin, but these activities varied with individual isolates. Analysis of six clinical and two environmental isolates with various levels of phospholipase activity indicated a correlation between phospholipase activity and the ability to adhere to the lung epithelial cell line, A549. The extent of cell damage, as indicated by lactate dehydrogenase release, also paralleled the phospholipase activity of these isolates. In addition, production of melanin contributed significant protection against amphotericin B killing of the isolates tested. [source] | ||||||||||