Antifungal susceptibilities and identification of Candida species by using maldi-tof microbial identification system from cervicovaginal samples

Background: Among the vaginal diseases seen in women, candidiasis is in the first place. This disease, which is caused by Candida species, can sometimes persist very stubbornly. The aim of this study was to determine Candida species isolated from vaginal specimens by using VITEK MS (MALDI-TOF Microbial Identification System) rapid identification system and to evaluate their susceptibility to some antifungals.Methods: In this study, 220 cervicovaginal swab were used. Isolates were identified by VITEK MS rapid identification system. After identification, antifungal susceptibility testing was performed using the M-44 A2 guideline of The Clinical and Laboratory Standards Institute (CLSI).Results: Total 16.3% (36) of Candida spp. positivity was determined from 220 cervicovaginal samples, and 25 (69.4%) C. glabrata, 6 (16.7%) C. albicans, 3 (8.3%) C. kefyr and 2 (5.6%) C. krusei were obtained with Vitek MS. All identified C. albicans strains were found to be completely resistant to all antifungals used except nystatin agent, C. krusei strains were found to be resistant to flucytosine but sensitive to all other antifungals, C. glabrata and C. kefyr strains were susceptible to all antifungals within the antifungals used in this study.Conclusions: It is concluded that it is necessary to distinguish Candida species in order to apply a correct treatment. And species selection is very important for the selection of antifungal to be used. Nystatin is recommended if no laboratory tests are to be performed for the diagnosis of Vaginal Candidiasis.

Isolation and Identification of Bacillus from Spontaneous Fermented Sufu

Sufu is a traditional Chinese fermented food. The safety of spontaneous fermentation products has been concerned by more and more people. A total of four isolates with big clear halos on the casein medium plate were isolated from spontaneous fermented Sufu in southern Sichuan. A1 and A3 most likely belong to Bacillus cereus B according to their phenotype and Biolog Microbial Identification System. B2 was classified in group as Bacillus amyloliquefaciens B with the same methods. A2 was identified as Bacillus subtilis according to their phenotype and 16SrRNA. The safety of the strains are also discussed.

Grain Discoloration of Rice Caused by Pantoea ananatis (synonym Erwinia uredovora) in China

In the autumn of 2008, a new bacterial disease of rice was noted in paddy fields near Hangzhou, Zhejiang Province, China. The disease caused severe discoloration of rice grains on cv. Zhong-zhe-you 1 (Oryza sativa L.). It often occurred at early flowering of hybrid rice. Initially, light, rusty, water-soaked lesions appeared on the lemma or palea and then turned brown. More immature and lighter grains were observed on panicles at harvest. No bacterial ooze was observed. Ten bacterial isolates were recovered from eight samples of discolored rice grains (1). Six isolates were selected for identification. They were similar to those of the reference strain of Pantoea ananatis (Serrano, synonym Erwinia uredovora) LMG 2665T (ATCC 33244) from Belgium in phenotypic tests based on the Biolog Microbial Identification System, version 4.2 (Biolog Inc., Hayward, CA), pathogenicity tests, gas chromatographic analysis of fatty acid methyl esters (FAME) using the Microbial Identification System (MIDI Inc, Newark, DE) with the aerobic bacterial library (TAB 5.0), and electron microscopy (TEM,KYKY-1000B, Japan). All isolates were facultatively anaerobic, gram-negative rods that measured 1.6 to 2.5 × 0.5 to 0.7 μm and had three to six peritrichous flagella. Colonies on nutrient agar were yellow and raised with smooth margins. A hypersensitive reaction was observed on tobacco (Nicotiana tobacum cv. Benshi) 24 h after inoculation. All isolates were identified as P. ananatis with Biolog similarity indices of 0.716 to 0.852 and FAME similarity indices of 0.783 to 0.903. Further identification as P. ananatis was done by 16S rDNA sequence analysis. Amplicons were produced from three strains using the universal primers (3) fD2: 5′-AGA GTT TGA TCA TGG CTC AG-3′ forward primer and rP1: 5′-ACG GTT ACC TTG TTA CGA CTT-3′ reverse primer and then sequenced (GenBank Accession Nos. GU324769, GU324770, and GU338399). A BlastN search of GenBank revealed that they had 97 to 98% nt identity with P. ananatis strain 3Pe76 (GenBank Accession No. EF178449). Koch's postulates were completed by spray inoculating panicles of rice cv. Zhong-zhe-you 1 at booting stage, grown in pots, with cell suspensions containing 108 CFU/ml of the six strains at 25 to 29°C. Three plants were inoculated with each strain, controls were sprayed with water, and the experiment was repeated once. Three weeks after inoculation, all strains produced symptoms on panicles similar to those observed in the field. Yellow pigmented bacteria were reisolated from symptomatic panicles and their identity was confirmed by FAMEs. These results indicate that the pathogen is P. ananatis (2), which also causes leaf blight and bulb decay of onion. To our knowledge, this is the first report of rice grain discoloration caused by P. ananatis in China. The disease cycle on rice and the control strategies in the regions are being further studied. References: (1) J. Y. Luo et al. Plant Dis. 91:1363, 2007. (2) H. G. Truper and L. de Clari. Int. J. Syst. Bacteriol. 47:908, 1997. (3) W. G. Weisburg et al. J. Bacteriol. 173:697, 1991.

First Report of Bacterial Head Rot of Broccoli Caused by Pseudomonas fluorescens in China

During warm and humid periods in the winters from 2005 to 2008, head rot symptoms on broccoli (cv. Sijilv) (Brassica oleracea L. var italica Planch) were observed in commercial fields in Ningbo, Zhejiang Province, China. In agreement with the report of Cui and Harling (1), water-soaked lesions developed on the buds and then progressed into a brown-black soft rot. Longitudinal sections of the symptomatic inflorescences showed brown discoloration and rotting of the internal tissues. Broccoli production is hampered by the disease, with disease incidence ranging from 65 to 81%. Bacteria were isolated by streaking on nutrient agar (3) and individual colonies formed after 2 to 3 days of incubation at 28°C. Fifteen of thirty isolates induced hypersensitive reactions (HR) on tobacco leaves (Nicotiana tabacum cv. Samsun) within 48 h. All the HR-positive strains were fluorescent on King's medium B and the colonies were smooth, convex, entire, and round. Classical bacteriological tests indicated that the fluorescent strains were gram negative, obligate aerobes, arginine dihydrolase positive, and oxidase positive. Also, the fluorescent strains were positive for the production of levan from sucrose. Five representative strains were further characterized by the Biolog Microbial Identification System, version 4.2 (Biolog Inc., Hayward, CA) and gas chromatography of fatty acid methyl esters (FAME) using the Microbial Identification System (MIDI Inc., Newark, DE) with the aerobic bacterial library (TSBA50). The five strains were identified as Pseudomonas fluorescens with Biolog and FAME similarity indexes of 0.61 to 0.68 and 0.52 to 0.58, respectively. The 16S rRNA gene sequence of broccoli strain PFB-01 (GenBank Accession No. GQ352649) was determined according to Li et al. (2). A subsequent GenBank search showed that this sequence had 98% nucleotide identity with the type strain of P. fluorescens (ATCC 17386T, GenBank Accession No. AF094726). Koch's postulates were completed by the inoculation of broccoli heads (cv. Sijilv) with cell suspensions (107 CFU/ml) of the above five strains by spraying on the surface of subcorymbs. Each treatment had five replicates. All strains induced head rot symptoms similar to those observed in natural infections. No symptoms were noted on the control plants inoculated with sterile water. Bacteria were successfully reisolated from symptomatic heads and confirmed by the cellular fatty acid composition. To our knowledge, this is the first report in China that P. fluorescens is the causal pathogen of bacterial head rot of broccoli. References: (1) X. Cui and R. Harling. Phytopathology 96:408, 2006. (2) B. Li et al. J. Phytopathol. 154:711, 2006. (3) N. W. Schaad et al. Laboratory Guide for Identification of Plant Pathogenic Bacteria. 3rd ed. The American Phytopathological Society. St. Paul, MN, 2001.