scholarly journals Investigation of the relationship between virulence factors and genotype of Candida spp. isolated from blood cultures

2015 ◽  
Vol 9 (08) ◽  
pp. 857-864 ◽  
Author(s):  
Fatma Mutlu Sariguzel ◽  
Elife Berk ◽  
Ayse Nedret Koc ◽  
Hafize Sav ◽  
Gonca Demir

Introduction: The aim of study was to investigate the virulence factors of phospholipase, proteinase, esterase production and biofilm formation in Candida species isolated from patients with candidemia, and to assess their relationship with Candida genotypes derived after repetitive sequence-based polymerase chain reaction (rep-PCR) fingerprinting. Methodology: Fifty-two strains were identified to species level according to conventional methods and sequencing. The DiversiLab system was used for the genotyping. Enzyme activities and biofilm formation were evaluated using microbiological methods. Results: The 52 strains were identified as follows: 29 C. parapsilosis, 19 C. albicans, 2 C. glabrata, and 2 C. tropicalis. Phospholipase and proteinase activities were observed to have statistically significant differences between C. albicans and non-albicans Candida (NAC) strains (p < 0.05), with C. albicans strains showing higher virulence. Rep-PCR revealed eight major genotypes (A-H).The 19 C. albicans and the 33 non-albicans Candida isolates yielded seven (A-G) and four (A, B, C, H) genotypes, respectively. C. albicans strains were not shown to have a predominant genotype and showed higher phospholipase and proteinase activitiy than did NAC, regardless of genotype. Genotype H (52%) was the predominant genotype for the NAC including 27 C. parapsilosis strains, but the majority of strains showed low virulence. Conclusions: NAC species were the most common causative agent for candidemia. Genotyping showed low transmission of C. albicans strains, but transmission of C. parapsilosis was high. In candidemia, several Candida virulence factors may be responsible at the same time. However, different genotypes of Candida strains showed different virulence activity.

Author(s):  
Nguyen Duy Bac1 ◽  
Le Tran Anh2 ◽  
Le Bach Quang ◽  
Nguyen Khac Luc ◽  
Tran Thi ◽  
...  

Background and Objectives: Identification of yeasts provides helpful information for appropriate administration of an- ti-fungal treatments; however, few reports from the Vietnam have been published. This study has been performed to find the prevalence of Candida blood stream isolates from patients in two hospitals in Vietnam. Materials and Methods: Candida spp. were isolated from blood cultures in two hospitals, Vietnam between May 2013 and May 2015. Participating hospitals were 103 Military Hospital, Ha Noi city (550 beds) and Cho Ray Hospital, Ho Chi Minh city (1800 beds). All the bloodstream isolates were identified to species level by the germ tube test and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In addition, unknown isolates were subjected to PCR sequencing. Results: A total of 93 Candida isolates were isolated from blood cultures during the study period. The results of this study showed that C. tropicalis (n = 47, 50.54%) was the most common agent, followed by Candida albicans/dubliniensis (n = 18, 19.35%), C. parapsilosis (n = 16, 17.20%), C. glabrata (n = 6, 6.45%), C. mesorugosa (n = 5, 5.38%) and C. krusei (n = 1, 1.08%), respectively. Conclusion: The frequency of the non-albicans Candida species in blood is increasing, especially C. tropicalis. Addi- tional investigations should be made to clarify the epidemiological profile of invasive Candida bloodstream in Vietnam.


Author(s):  
Rasoul Ghaioumy ◽  
Fatemehalsadat Tabatabaeifar ◽  
Karamat Mozafarinia ◽  
Aliasghar Arabi Mianroodi ◽  
Elham Isaei ◽  
...  

Background and Objectives: It is well known that Staphylococcus aureus biofilm plays an important role in adenoiditis and biofilm resistance frequently results in failure of therapy. The goal of this study was to evaluate the biofilm production of S. aureus isolates obtained from adenoid specimens and assess the relationship between biofilm formation ability and ica operon genes. Materials and Methods: A total of 112 adenoid samples were obtained from patients under 15 years old with adenoid hypertrophy. All S. aureus isolates were initially identified by standard microbiological tests and amplification of nuc by polymerase chain reaction (PCR) technique. Biofilm formation of S. aureus isolates was evaluated and icaADBC genes were detected by PCR technique. Results: There were 46 isolates (41%) identified as S. aureus. The ability to produce biofilm was detected among total S. aureus isolates. Molecular study of ica operon revealed that 2 (6.3%) and 19 (59.4%) isolates carried icaA and icaD, respec- tively. The prevalence of icaA + icaD was seen among 11 (34.4%) S. aureus isolates, while icaC and icaB were not detected. Conclusion: Our findings indicated that icaABCD operon are associated with biofilm formation in S. aureus isolates, how- ever the absence of these genes may not necessarily exclude this property.  


Author(s):  
Fatima Abdul Hussein Mejbel

 During the period from September 2016 to December 2017,135 urine samples were collected from urinary tract infection patients attending to AL-Zahraa Hospital in AL-Najaf Governorate. The present study was conducted to isolate and identify Candida spp. isolated from urinary tract infection patients by different methods including direct examination, laboratory culture, biochemical test and by modern techniques (Api Candida kit) and determine the virulence factors phenotypic to Candida spp which involved (biofilm formation,phospholipase and germ tube). The percentage of females to males was as following, female (84) 62.2 % (21) infected and male (51) 37.8% (1) infected with all age categories. The results in this study are explain that is some Candida spp. such as C. albicans, have high susceptible to eugenole follow by phenol and umbellulone. The efficiency of some chemical substances such as (eugenole,umbellulone, and phenol) was evaluated to inhibit the growth of Candida ssp as well as some virulence factors such as biofilm formation,germ tube and phospholipase,which were studied in this research. Statistically analysis results have been significance difference between the results of the substance concentrations and the concentrations of the different other substances.


Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 466
Author(s):  
Martyna Mroczyńska ◽  
Anna Brillowska-Dąbrowska

The factors enabling Candida spp. infections are secretion of hydrolytic enzymes, adherence to surfaces, biofilm formation or morphological transition, and fitness attributes. The aim of this study was to investigate the correlation between known extracellular virulence factors and survival of Galleria mellonella larvae infected with clinical Candida. The 25 isolates were tested and the activity of proteinases among 24/24, phospholipases among 7/22, esterases among 14/23, hemolysins among 18/24, and biofilm formation ability among 18/25 isolates was confirmed. Pathogenicity investigation using G. mellonella larvae as host model demonstrated that C. albicans isolates and C. glabrata isolate were the most virulent and C. krusei isolates were avirulent. C. parapsilosis virulence was identified as varied, C. inconspicua were moderately virulent, and one C. palmioleophila isolate was of low virulence and the remaining isolates of this species were moderately virulent. According to our study, virulence of Candida isolates is related to the expression of proteases, hemolysins, and esterases.


1997 ◽  
Vol 76 (7) ◽  
pp. 1376-1380 ◽  
Author(s):  
J.H. Meurman ◽  
J. Wahlfors ◽  
A. Korhonen ◽  
P. Alakuijala ◽  
P. Väisänen ◽  
...  

Bacteroides forsythus has been shown to be prevalent among patients with periodontitis. Conventional microbiological methods used to identify this bacterium, however, are laborious and time-consuming and are therefore not well-suited for screening purposes. We have developed a polymerase chain-reaction (PCR) method which is rapid, specific, and simple to perform and does not require other sample pre-treatment except a brief centrifugation. This method was applied to the detection of B. forsythus in subgingival plaque of 58 periodontitis patients. When compared with the results of conventional culturing, the PCR method always confirmed the culture-positive results, while none of the PCR negative samples was shown to be culture-positive. The PCR method appeared to give more than double the number of samples positive for B. forsythus than culturing (89.7% vs. 37.9%). The analysis requires less than 4 hrs to perform, and is specific only to B. forsythus and sensitive enough to detect fewer than 5 bacteria.


2008 ◽  
Vol 60 (3) ◽  
pp. 263-271 ◽  
Author(s):  
Catherine Dunyach ◽  
Sébastien Bertout ◽  
Cécile Phelipeau ◽  
Pascal Drakulovski ◽  
Jacques Reynes ◽  
...  

2021 ◽  
Vol 15 ◽  
Author(s):  
Sara Galeb ◽  
Maysaa El Sayed Zaki ◽  
Raghdaa Shrief ◽  
Rasha Hassan ◽  
Mohamed Anies

Background: Proper identification of the causative organism in pediatric sepsis is crucial for early diagnosis and prevention of septic shock and organ failure. Objectives: The present study aimed to evaluate the multiplex Polymerase Chain Reaction (PCR) to detect Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia from positive blood cultures for these pathogens isolated from children, with hospital-acquired sepsis compared to the conventional biochemical reactions for identification of these organisms. Methods: This study was a cross-sectional study performed on 100 isolates from pediatric blood cultures, including Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. The study also included 100 isolates of Escherichia coli as a negative control. All isolates were identified by API 20NE and the multiplex PCR, with primers specific to the 3 tested bacteria. Results: Multiplex PCR was positive in 96% of isolates, and 4 isolates had negative results. False positive results were reported with three E. coli strains. Multiplex PCR identified all the isolates of Acinetobacter baumannii, 29 isolates of Pseudomonas aeruginosa, and 27 isolates of Stenotrophomonas maltophilia. Compared to the biochemical identification, the diagnostic value of the multiplex PCR revealed 96.04% sensitivity, 96.9% specificity, 97.00%, positive predictive value, 96.00% negative predictive value, and 96.50% accuracy. Conclusion: The present study highlights the diagnostic value of multiplex PCR to identify Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia from positive blood cultures. Multiplex PCR was sensitive, specific, and accurate. The accuracy differs according to the organisms, with 100% accuracy for Acinetobacter baumannii.


2018 ◽  
Vol 35 (1) ◽  
pp. 11-19
Author(s):  
Kuder Reshma Shabnam ◽  
Dharmapuri Gangappa ◽  
Gundala Harold Philip

Evaluation of the toxic effects of a widely used synthetic pyrethroid, deltamethrin (DM), was carried out in this study. This pesticide is preferred for pest control because of its low environmental persistence and toxicity. We investigated the expression pattern of four genes, namely, you ( you), yot ( you-too), momo ( mom) and ubo ( u-boot) during early development of zebrafish, that is, from 12 hpf to 48 hpf stages. These stages are selected as most of the important developmental aspects take place during this period. All four genes are known to play a vital role in development of notochord and somites. To understand the effect of DM on development, embryos of 4 hpf stage were exposed to two concentrations (100 and 200 µg/L) of DM, and observations were made at 12, 24 and 48 hpf stages. Our earlier studies have shown phenotypic abnormalities such as notochord bending, tail deformation, yolk sac and pericardial edema, lightening of body and eye pigmentation and interfered in somite patterning, during these stages of development. Understanding the relationship of phenotypic abnormalities with these four genes has been our primary objective. These four genes were analyzed by Reverse transcription (RT)-polymerase chain reaction and intensity of the bands has shown induction in their expression after exposure to the toxicant. In spite of the expression of genes, it was noticed that DM caused abnormalities. It can be said from the results that translational pathway could have been affected.


Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 187
Author(s):  
Ying Xu ◽  
Zhen Zhang ◽  
Zhen Su ◽  
Xiaoxiang Zhou ◽  
Xiaoming Han ◽  
...  

Automatic microfluidic purification of nucleic acid is predictable to reduce the input of original samples and improve the throughput of library preparation for sequencing. Here, we propose a novel microfluidic system using an external NdFeB magnet to isolate DNA from the polymerase chain reaction (PCR) mixture. The DNA was purified and isolated when the DNA-carrying beads transported to the interface of multi-laminar flow under the influence of magnetic field. Prior to the DNA recovery experiments, COMSOL simulations were carried out to study the relationship between trajectory of beads and magnet positions as well as fluid velocities. Afterwards, the experiments to study the influence of varying velocities and input of samples on the DNA recovery were conducted. Compared to experimental results, the relative error of the final position of beads is less than 10%. The recovery efficiency decreases with increase of input or fluid velocity, and the maximum DNA recovery efficiency is 98.4% with input of l00 ng DNA at fluid velocity of 1.373 mm/s. The results show that simulations significantly reduce the time for parameter adjustment in experiments. In addition, this platform uses a basic two-layer chip to realize automatic DNA isolation without any other liquid switch value or magnet controller.


Open Medicine ◽  
2008 ◽  
Vol 3 (4) ◽  
pp. 470-474 ◽  
Author(s):  
Ilker Devrim ◽  
Koray Ergünay ◽  
Ates Kara ◽  
Hasan Tezer ◽  
Inci Yiğitkanl ◽  
...  

AbstractTyphoid fever caused by Salmonella typhi, paratyphi A and B, is an important cause of morbidity and mortality in many developing countries. A rapid and sensitive method for the detection of S. typhi is essential for early diagnosis of typhoid fever and effective therapy. In this study 45 febrile patients who were suspected to have enteric fever were enrolled, and the results of blood cultures, widal agglutination tests and Polymerase Chain Reaction in these cases were evaluated. Group I consisted of 11 patients with diseases other than salmonella infections, group II represented 6 patients with positive cultures, and group III represented 28 patients with negative blood cultures negative but who were clinically suspected cases that had a medical history of using variable antimicrobial agents. Two positive PCR results were present; one of them was in culture positive group (16,6%) and the other was in culture negative group (3,5%). In our study widal agglutination tests and cultures were found not to be helpful in differential dignosis. Although PCR based detection of S. typhi is reported to be a sensitive and specific test for the diagnosis of enteric fever, in our study the benefit of this method in the diagnosis of especially patients who were treated with antimicrobial therapy was not clearly determined. Other methods to increase sensitiviy and specificity to levels such as those of real time PCR should be developed and large-scaled studies should be done in endemic and non-epidemic regions.


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