scholarly journals Low prevalence of Moraxella catarrhalis in the patients who suffered from conjunctivitis in the southwest of Iran

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ahmad Farajzadeh Sheikh ◽  
Mustafa Feghhi ◽  
Maryam Torabipour ◽  
Morteza Saki ◽  
Hojat Veisi
Keyword(s):  
Moraxella Catarrhalis ◽  
Positive Culture ◽  
Culture Method ◽  
Specific Gene ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Southwest Of Iran ◽  
Human Infections ◽  
Low Prevalence ◽  
Positive Results

Abstract Objective Moraxella catarrhalis is a non-motile Gram-negative diplococcus bacterium that contributed to several human infections including conjunctivitis. This study aimed to reveal the prevalence of M. catarrhalis in patients who suffered from conjunctivitis in Ahvaz city, southwest of Iran. Results Out of 100 conjunctiva swab specimens, M. catarrhalis was isolated only from one (1%) conjunctivitis cases using the culture method. This strain was isolated from a 34 years old female patient. Also, the results of the polymerase chain reaction (PCR) were in agreement with the culture method, and the specimen that showed positive culture was also positive for specific gene of M. catarrhalis. The remaining 99 specimens did not show positive results with any of the culture and PCR methods.

scholarly journals Diagnostic Evaluation of Streptococcus gallolyticus Infection in Patients with Colon Diseases by Polymerase Chain Reaction (PCR) and Culturing Methods

2020 ◽  
Vol 13 (6) ◽  
Author(s):  
Foroogh Eshaghi ◽  
Haniyeh Bashi Zadeh Fakhar ◽  
Masood Ghane ◽  
Javad Shokry
Keyword(s):  
Polymerase Chain Reaction ◽  
Brain Heart Infusion ◽  
Positive Culture ◽  
Culture Method ◽  
Standard Test ◽  
Culture Technique ◽  
Chain Reaction ◽  
Streptococcus Gallolyticus ◽  
Polymerase Chain ◽  
Colon Diseases

Background: Different types of Streptococcus gallolyticus are associated with malignant bowel cancer. Objectives: The aim of this study was to compare two culture and molecular methods in identifying Streptococcus gallolyticus in patients with colon diseases. Methods: A descriptive study was conducted to detect Streptococcus gallolyticus in 55 patients with colon diseases referring to hospitals in Babol and Chalus, Iran. A polymerase chain reaction and culture technique were performed. Detection of Streptococcus gallolyticus after deoxyribonucleic acid (DNA) extraction from designed primers (PCO3, PCO4) was used for SODA gene. From the general culture medium, brain heart infusion (BHI) broth and specific medium for bacterial growth and detection were used. Then, the characteristics of the two methods were evaluated. Results: Of 55 biopsy samples of patients with colon diseases, 3 samples (5.5%) with 95% confidence interval were positive and 52 (94.5%) were reported negative in terms of DNA of Streptococcus gallolyticus. According to the culture test, 9 (16.4%) were positive and 46 (83.6%) were negative for diagnosis of Streptococcus gallolyticus bacteria. Based on the diagnostic agreement between the two methods, the ratio of 9 positive cases of culture method to 3 positive cases by polymerase chain reaction (PCR) method (3.6%) were reported positive both in terms of molecular and positive culture, and 7 (12.7%) out of 9 (16.4%) were negative. To investigate the agreement between the culture and PCR methods, the Kappa test was used, which was statistically significant (P < 0.015). Other studies which have been conducted using the culture method, reported a significant relationship between the family history of colorectal cancer, diabetes, and the presence of Streptococcus gallolyticus bacteria. Conclusions: Considering the advantages, disadvantages, and the characteristics of both methods, none of them can be considered as a comprehensive, standard test at present. The simultaneous use of the two methods is recommended in cases where achieving fast results prevails, or when there is a likelihood of sample infection or late-growing microorganisms.

scholarly journals COVID-19 Preprocedural Testing: What About the False Positives?

2021 ◽  
pp. 019459982199510
Author(s):  
Christopher J. Hill ◽  
Charles D. Meyer ◽  
Marilisa G. Elrod ◽  
Gregory G. Capra
Keyword(s):  
Diagnostic Testing ◽  
Mitigation Strategy ◽  
Pretest Probability ◽  
Test Results ◽  
Chain Reaction ◽  
Polymerase Chain Reaction Testing ◽  
Asymptomatic Patients ◽  
Polymerase Chain ◽  
Low Prevalence ◽  
Positive Results

In the COVID-19 era, preprocedural patients are almost uniformly screened for symptoms, asked to quarantine preoperatively, and then undergo a test of uncertain validity with very low pretest probability. A small percentage of these tests return positive. As a result, surgical procedures are delayed and patients are required to quarantine. Are these asymptomatic patients truly positive for COVID-19? What are the impacts of these test results on the patient and the health care system? In the following commentary, we review how the uncertain validity of reverse transcription polymerase chain reaction testing combined with a low-prevalence population predisposes for false-positive results. As a mitigation strategy, we ask that readers refocus on the fundamental principal of diagnostic testing: pretest probability.

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.

Detection of specific mRNAs in single nephron segments by use of the polymerase chain reaction

1990 ◽  
Vol 258 (5) ◽  
pp. F1470-F1474 ◽  
Author(s):  
T. Moriyama ◽  
H. R. Murphy ◽  
B. M. Martin ◽  
A. Garcia-Perez
Keyword(s):  
Polymerase Chain Reaction ◽  
Aldose Reductase ◽  
Collecting Duct ◽  
Specific Gene ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Nephron Segments ◽  
Single Nephron ◽  
Specific Mrnas ◽  
Polymerase Chain

We have developed a procedure to detect specific mRNAs in single renal nephron segments. This approach combines microdissection, reverse transcription (RT) of the target mRNA, and amplification of the resulting cDNA using the polymerase chain reaction (PCR). After microdissection, the sample is placed in a tube where it is permeabilized and where all reactions are performed directly without the need for isolation of the RNA. Our model target was the mRNA for aldose reductase. This enzyme catalyzes the conversion of glucose to sorbitol. Its expression is modulated by changes in extracellular osmolality in the renal medulla. RT-PCR of inner medullary collecting duct (1 mm) and glomeruli (6-10) yielded a product of the predicted length (670 base pairs) defined by the PCR primers. Its identity was confirmed by a specific oligonucleotide probe that differed from the primers. RT-PCR of proximal tubules (1 mm) resulted in no aldose reductase-specific amplification product. RT-PCR is generally applicable for measuring specific gene expression in single nephron segments or small numbers of cultured cells. Utility, limitations, and refinements of this approach are discussed.

Identification of Bacteroides forsythus in Subgingival Dental Plaque with the Aid of a Rapid PCR Method

1997 ◽  
Vol 76 (7) ◽  
pp. 1376-1380 ◽  
Author(s):  
J.H. Meurman ◽  
J. Wahlfors ◽  
A. Korhonen ◽  
P. Alakuijala ◽  
P. Väisänen ◽  
...  
Keyword(s):  
Dental Plaque ◽  
Subgingival Plaque ◽  
Chain Reaction ◽  
Rapid Pcr ◽  
Microbiological Methods ◽  
Pcr Method ◽  
Polymerase Chain ◽  
Pre Treatment ◽  
Culture Positive ◽  
Positive Results

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.

Studies on Diagnosis of Bovine Brucellosis by Immunocyto-chemistry and Immunohistochemistry

2021 ◽  
Author(s):  
K.S. Lakshmikanth ◽  
N.S. Sharma ◽  
D. Pathak ◽  
Paviter Kaur
Keyword(s):  
Biochemical Analysis ◽  
Placental Tissue ◽  
Diagnostic Techniques ◽  
Clinical Samples ◽  
Bovine Brucellosis ◽  
Reproductive Disorders ◽  
Chain Reaction ◽  
Tissue Samples ◽  
Polymerase Chain ◽  
Positive Results

Background: Brucellosis is a major threat to livestock economy and an important zoonotic disease. A rapid and accurate diagnosis is a necessity to curb the spread and progress of the disease. The current study aimed to evaluate sensitivity of Immunocytochemistry and Immunohistochemistry methods for detection of Brucella spp.Methods: A total of 50 samples comprising of fetal stomach content, vaginal discharges and placenta were collected from cattle and buffaloes suffering from abortions and other reproductive disorders in and around Ludhiana, Punjab during the period 2017-2018. All the samples were processed for isolation and confirmed with biochemical analysis and Polymerase chain reaction (PCR). The isolates obtained and 43 clinical samples excluding placental samples were subjected to Immunocytochemistry (ICC). Immunohistochemistry (ICH) was performed on placental samples.Result: A total of four isolates were recovered from the screened samples. The four isolates also yielded positive results in Immunocytochemistry. Among the 43 clinical samples screened by Immunocytochemistry, five were positive, however only 3 isolates were recovered on isolation. A total of seven placental tissue samples were processed and subjected to immunohistochemistry. Of the three placental samples positive by immunohistochemistry, only one sample was isolated on culture. The results suggest that both immunocytochemistry and immunohistochemistry are sensitive diagnostic techniques in comparison to isolation.

scholarly journals PCR - based diagnosis to evaluate the performance of malaria reference centers

2004 ◽  
Vol 46 (4) ◽  
pp. 183-187 ◽  
Author(s):  
Silvia Maria Di Santi ◽  
Karin Kirchgatter ◽  
Karen Cristina Sant'Anna Brunialti ◽  
Alessandra Mota Oliveira ◽  
Sergio Roberto Santos Ferreira ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Gold Standard ◽  
Blood Smear ◽  
Plasmodium Species ◽  
Thick Blood Smear ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Positive Results ◽  
Ssrrna Gene

Although the Giemsa-stained thick blood smear (GTS) remains the gold standard for the diagnosis of malaria, molecular methods are more sensitive and specific to detect parasites and can be used at reference centers to evaluate the performance of microscopy. The description of the Plasmodium falciparum, P. vivax, P. malariae and P. ovale ssrRNA gene sequences allowed the development of a polymerase chain reaction (PCR) that had been used to differentiate the four species. The objective of this study was to determine Plasmodium species through PCR in 190 positive smears from patients in order to verify the quality of diagnosis at SUCEN's Malaria Laboratory. Considering only the 131 positive results in both techniques, GTS detected 4.6% of mixed and 3.1% of P. malariae infections whereas PCR identified 19.1% and 13.8%, respectively.

scholarly journals Discovery of Cocirculating Ross River Virus and Barmah Forest Virus At Wide Bay Military Training Area, Northeastern Australia

2019 ◽  
Vol 35 (3) ◽  
pp. 220-223
Author(s):  
Jo Kizu ◽  
Christina Neuman ◽  
Luke Le Grand ◽  
Wenjun Liu
Keyword(s):  
Polymerase Chain Reaction ◽  
Phylogenetic Analysis ◽  
Military Training ◽  
Ross River Virus ◽  
Chain Reaction ◽  
Culex Annulirostris ◽  
Australian Defence Force ◽  
Polymerase Chain ◽  
Human Infections ◽  
Training Area

ABSTRACT An arbovirus surveillance military exercise was conducted to assess the risk of Ross River virus (RRV) and Barmah Forest virus (BFV) in the Australian Defence Force (ADF) Wide Bay training area (WBTA), northeastern Australia, in April 2018. Of the 5,540 female mosquitoes collected, 3,702 were screened for RRV and BFV by quantitative reverse transcription–polymerase chain reaction in a field laboratory. One pool of Verrallina funerea was positive for RRV and 8 pools (7 pools of Aedes vigilax and 1 pool of Culex annulirostris) were positive for BFV. Phylogenetic analysis of the complete nucleotide sequence of the E2 protein subgrouped both RRV and BFV with viruses previously isolated from human infections, indicating the potential risk of RRV and BFV infection to ADF personnel while training in WBTA. This is the 1st time that both RRV and BFV have been detected in a military training area.

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