Use of Nested Polymerase Chain Reaction Based on Sequence-Based Typing of Clinical Samples to Determine the Source of Infection for Hospital-Acquired Legionnaires' Disease

2011 ◽  
Vol 32 (5) ◽  
pp. 510-512 ◽  
Author(s):  
Maria Scaturro ◽  
Stefano Fontana ◽  
Maria Luisa Ricci
Keyword(s):  
Polymerase Chain Reaction ◽  
Clinical Samples ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Tissue Samples ◽  
Source Of Infection ◽  
Disease Case ◽  
Legionnaires Disease ◽  
Polymerase Chain ◽  
Hospital Acquired

The source of infection of a hospital-acquired Legionnaires' disease case was determined for the first time by nested polymerase chain reaction based on sequence-based typing. The typing was performed directly on DNA extracted from tissue samples, allowing a rapid epidemiological correlation with environmental isolates.

Using a Polymerase Chain Reaction as a Complementary Test to Improve the Detection of Dermatophyte Fungus in Nails

2014 ◽  
Vol 104 (3) ◽  
pp. 233-237 ◽  
Author(s):  
María José Iglesias Sánchez ◽  
Ana María Pérez Pico ◽  
Félix Marcos Tejedor ◽  
María Jesús Iglesias Sánchez ◽  
Raquel Mayordomo Acevedo
Keyword(s):  
Polymerase Chain Reaction ◽  
Dna Sequences ◽  
Classical Method ◽  
Clinical Manifestations ◽  
Culture Method ◽  
Clinical Samples ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Traditional Procedure ◽  
Polymerase Chain

Background Dermatomycoses are a group of pathologic abnormalities frequently seen in clinical practice, and their prevalence has increased in recent decades. Diagnostic confirmation of mycotic infection in nails is essential because there are several pathologic conditions with similar clinical manifestations. The classical method for confirming the presence of fungus in nail is microbiological culture and the identification of morphological structures by microscopy. Methods We devised a nested polymerase chain reaction (PCR) that amplifies specific DNA sequences of dermatophyte fungus that is notably faster than the 3 to 4 weeks that the traditional procedure takes. We compared this new technique and the conventional plate culture method in 225 nail samples. The results were subjected to statistical analysis. Results We found concordance in 78.2% of the samples analyzed by the two methods and increased sensitivity when simultaneously using the two methods to analyze clinical samples. Now we can confirm the presence of dermatophyte fungus in most of the positive samples in just 24 hours, and we have to wait for the result of culture only in negative PCR cases. Conclusions Although this PCR cannot, at present, substitute for the traditional culture method in the detection of dermatophyte infection of the nails, it can be used as a complementary technique because its main advantage lies in the significant reduction of time used for diagnosis, in addition to higher sensitivity.

scholarly journals Development and application of polymerase chain reaction test for detection of Conidiobolus lamprauges

2013 ◽  
Vol 33 (12) ◽  
pp. 1448-1452 ◽  
Author(s):  
Marcelo M. Silveira ◽  
Daphine A.J. Paula ◽  
Maria C. Silva ◽  
Leticia C. Pitchenin ◽  
Raquel A.S. Cruz ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Clinical Signs ◽  
High Sensitivity ◽  
Polymerase Chain Reaction Test ◽  
Universal Primers ◽  
Clinical Samples ◽  
Histopathological Analysis ◽  
Chain Reaction ◽  
Tissue Samples ◽  
Polymerase Chain

Conidiobolomycosis is a granulomatous disease caused by the fungus Conidiobolus spp. in humans and animals. Traditional technique for diagnosis of the disease is isolation of the agent associated with the presence of typical clinical signs and pathological conditions. The aim of this study was to describe the development of a specific polymerase chain reaction (PCR) test for Conidiobolus lamprauges to detect the fungus in clinical samples. Samples from suspected animals were collected and submitted to isolation, histopathological analysis and amplification by PCR. DNA from tissues was subjected to PCR with fungi universal primers 18S rDNA gene, and specific primers were designed based on the same gene in C. lamprauges that generated products of about 540 bp and 222 bp respectively. The culture was positive in 26.6% of clinical samples. The PCR technique for C. lamprauges showed amplification of DNA from fresh tissues (80%) and paraffin sections (44.4%). In conclusion, the PCR technique described here demonstrated a high sensitivity and specificity for detection of fungal DNA in tissue samples, providing a tool for the rapid diagnosis of C. lamprauges.

A report of swine erysipelas infection in an organised farm in Kerala

2019 ◽  
Author(s):  
S. Sankar ◽  
P.S. Reshma ◽  
N. Sarika ◽  
M.R. Roshin ◽  
R. Niranjana ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Skin Infections ◽  
Post Mortem ◽  
Erysipelothrix Rhusiopathiae ◽  
Chain Reaction ◽  
Tissue Samples ◽  
Biochemical Characteristics ◽  
Source Of Infection ◽  
Polymerase Chain ◽  
Swine Erysipelas

Erysipelothrix rhusiopathiae is an established animal pathogen causing erysipelas in animals and occasionally it causes zoonotic skin infections in humans, known as erysipeloid. The present study was aimed to investigate the cause of sudden mortality in a batch of gilts in an organised farm in Thrissur district of Kerala. The heart swabs and tissue samples (spleen, liver, lungs, and heart) collected during post-mortem examination yielded growth of small Gram positive, non-capsulated, spore forming pleomorphic bacilli. Based on cultural, morphological and biochemical characteristics, these isolates were identified as E. rhusiopathiae. Furthermore, the isolates were subjected to Erysipelothrix specific 16S rRNA based polymerase chain reaction. The isolates were sequenced for further confirmation. The isolates were confirmed as E. rhusiopathiae by phenotypic and genotypic characterisation. Timely diagnosis of the disease helped to identify the possible source of infection. This study highlights the importance of timely identification of E. rhusiopathiae infection in an outbreak; thereby adequate strategies can be implemented to control the infection.

scholarly journals Comparison of polymerase chain reaction and Warthin-Starry techniques to detect Leptospira spp. in kidneys of slaughtered cattle

2014 ◽  
Vol 81 (1) ◽  
Author(s):  
Shahrzad Azizi ◽  
Reza Kheirandish ◽  
Elham Rahimi
Keyword(s):  
Polymerase Chain Reaction ◽  
Silver Staining ◽  
Direct Methods ◽  
Clinical Samples ◽  
Post Mortem ◽  
Chain Reaction ◽  
Silver Stain ◽  
Tissue Samples ◽  
White Spots ◽  
Polymerase Chain

Leptospirosis is a worldwide zoonotic disease that is caused by Gram-negative spirochaetes, Leptospira species. Affected animals excrete the organism in the urine into the environment and act as a source of infection. Cattle are maintenance hosts for some serovars of leptospirosis and are important in the transmission of the infection to humans. At post mortem examination, affected cattle show white spots in their kidneys but these are not specific for leptospirosis. Sometimes it is necessary that leptospirosis be diagnosed in the carcass. Different direct methods, including polymerase chain reaction (PCR), Warthin-Starry silver stain (WS), immunofluorescence (IF) and immunohistochemistry (IHC) can be used in order to diagnose leptospirosis in the affected tissues, such as kidney. The main advantage of the WS technique is direct visualisation of the bacteria in the tissue samples. Silver staining is useful for retrospective studies on formalin-fixed and paraffin-embedded samples but little information is available on the sensitivity and specificity of the technique. The present study aimed to find a simple and inexpensive method that can be used in any laboratory and that also, if clinical samples are not available, can detect Leptospira in tissue samples post mortem. This study was performed on 19 paraffin-embedded kidneys of slaughtered cows that grossly had focal to multifocal white spots. Leptospirosis was confirmed in these samples with PCR based on the LipL32 gene. Out of 19 PCR positive kidneys, Leptospira was identified in 13 stained samples by WS. The kidneys revealed different grades of interstitial nephritis. No relationship was found between severity of lesions and presence of leptospires in the kidneys. The PCR results on the urine and blood were consistent with matching WS stained kidneys. Out of 13 kidneys that were positive with silver staining, 7 matching blood and 10 matching urine samples were confirmed positive for leptospirosis with PCR. In this study, the WS technique provided fewer positive results than PCR. This may be as a result of a low burden of Leptospira in the kidney, but the sensitivity of WS staining needs more investigation.

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