scholarly journals POLYMERASE CHAIN REACTION DETECTION OF MYCOBACTERIUM TUBERCULOSIS FROM SPUTUM

2003 ◽  
Vol 42 (146) ◽  
pp. 65-70 ◽  
Author(s):  
Kun Young Sohn ◽  
S Shrestha ◽  
A Khagi ◽  
S S Malla ◽  
B M Pokharel ◽  
...  

ABSTRACTTuberculosis has remained to be a major public health problem in Nepal. The risk of spread of infection andemergence of drug-resistant strain has created the need for a rapid, sensitive and specific diagnostic test.In addition, clinically suspicious cases that do not give positive result in conventional laboratory test needmore sensitive test for diagnosis.In order to evaluate the possibility of incorporation of Polymerase Chain Reaction (PCR) in the diagnosis oftuberculosis, we performed a comparative study of PCR to detect Mycobacterium tuberculosis in sputumspecimens, against Ziehl-Neelsen (Z-N) stain and culture as a standard method.A total of 103 specimens were subjected to Z-N staining, culture and PCR for detecting Mycobacteriumtuberculosis. Of these, 19 were positive by Z-N stain, 26 by PCR and 25 by culture. Four stain negativespecimens showed positive result in both culture and PCR. Two specimens of stain and culture positive werePCR negative. Five specimens showed positive result only with PCR. Two culture positive specimens gavenegative results by both Z-N stain and PCR. Sensitivity, specificity, positive predictive value and negativepredictive value of PCR which were 84%, 93.5%, 80.8% and 94.9% respectively.This study showed that there is no need for PCR test for the smear positive cases. However, PCR could be apossible diagnostic tool for the confirmation of the smear negative cases that show clinical symptoms of TB.Key Words: Mycobacterium tuberculosis, Z-N stain, PCR, sensitivity, specificity.

Author(s):  
Mami Taniuchi ◽  
Kamrul Islam ◽  
Md Abu Sayeed ◽  
James A Platts-Mills ◽  
Md Taufiqul Islam ◽  
...  

Abstract Background Diarrhea remains a major public health problem and characterization of its etiology is needed to prioritize interventions. However, most data are from single-site studies of children. We tested samples from participants of any age from 11 geographically diverse hospitals in Bangladesh to describe pathogen-specific burdens of diarrhea. Methods We utilized 2 existing diarrhea surveillance systems: a Nationwide network at 10 sentinel hospitals and at the icddr,b hospital. We tested stools from enrolled participants and nondiarrheal controls for enteropathogens using quantitative polymerase chain reaction and calculated pathogen-specific attributable fractions (AFs) of diarrhea. Results We analyzed 5516 patients with diarrhea and 735 controls. Overall, rotavirus had the highest attributable burden of diarrhea (Nationwide AF, 17.7%; 95% confidence interval [CI], 14.3–20.9%; icddr,b AF, 39.9%; 38.0–41.8%), followed by adenovirus 40/41 (Nationwide AF, 17.9%; 95% CI: 13.9–21.9%; icddr,b AF, 16.6%; 95% CI, 14.4–19.4%) and Vibrio cholerae (Nationwide AF, 10.2%; 95% CI, 9.1–11.3%; icddr,b AF, 13.3%; 95% CI: 11.9–15.1%). Rotavirus was the leading pathogen in children <5 years and was consistent across the sites (coefficient of variation = 56.3%). Adenovirus 40/41 was the second leading pathogen in both children and adults. Vibrio cholerae was the leading pathogen in individuals >5 years old, but was more geographically variable (coefficient of variation = 71.5%). Other attributable pathogens included astrovirus, norovirus, Shigella, Salmonella, ETEC, sapovirus, and typical EPEC. Conclusions Rotavirus, adenovirus 40/41, and V. cholerae were the leading etiologies of infectious diarrhea requiring hospitalization in Bangladesh. Other pathogens were important in certain age groups or sites.


2014 ◽  
Vol 11 (1) ◽  
pp. 14-17 ◽  
Author(s):  
K Pandey ◽  
AK Mallik ◽  
S Pyakurel ◽  
SB Pun ◽  
BD Pandey

Background Visceral leishmaniasis is potentially fatal protozoan diseases caused by Leishmania donovani. Nepal is an endemic region in which visceral leishmaniasis causes a major public health problem in the lowland areas that border the endemic areas of Bihar state in India. Accurate diagnosis to inform treatment is a first step in achieving the goal of visceral leishmaniasis elimination from South East Asian regions by 2020. Objective The objective of the present study was to compare between the Microcopy and polymerase chain reaction for diagnosis of visceral leishmaniasis. Methods In the present study, 236 bone marrow aspirations were collected from suspected visceral leishmaniasis patients in Janakpur Zonal Hospital, Dhanusa district, Terai region of Nepal in between 2003-2007. We evaluated bone marrow samples by microscopic examination with subsequent testing of the same sample by polymerase chain reaction and sequence analysis. Results Giemsa’s solution stained bone marrow slides stored for over five years were used for polymerase chain reaction amplification. The result showed that 71% were polymerase chain reaction positive and 56% were microscopic positive. Out of 104 microscopic negative bone marrow samples, 15% of samples were positive by polymerase chain reaction. Conclusion Polymerase chain reaction could make a very good option for diagnosis by using less or non-invasive material from visceral leishmaniasis patients in endemic areas of Nepal. DOI: http://dx.doi.org/10.3126/kumj.v11i1.11016 Kathmandu University Medical Journal Vol.11(1) 2013: 14-17


2013 ◽  
Vol 12 (3) ◽  
pp. 325-330 ◽  
Author(s):  
Nazar M Abdalla ◽  
Abdelgani M Abdelgani ◽  
Amani A Osman ◽  
Mohamed A Sarhan

Objective: Leishmaniasis is a parasitic disease causing major public health problem in form of visceral and cutaneous types. The cutanoue leishmaniasis is caused by L. tropica, in low-land areas without reservoir; Arthroponatic leishmaniasis (ACL),  Zoonotic Cutaneous Leishmaniasis ( ZCL), in high-land. This case report involved; 25 years old Egyptian active young single male adult, stayed in Utama (75 Km far from El-Madina Manowra on the road to Makkah). He presented with three skin lesions on his arms occurred within the last 1-3 months. on examination revealed; volcano- like indurated ulcers which clinically suspected as leishmania lesions .Materials and Methods: Laboratory investigations were involved; skin smear using Giemsa stain, Leishmanin test (LST),  polymerase chain reaction (PCR), sequencing and phylogenitic analysis BLAST (NCBI).Results: Microscopy  positive LDB (leishmanin donovani bodies), Leishmanin test (LST) was negative. PCR  positive L. major . Sequence alignment were 100% with nine Iranian isolates and one Tunisian isolate. After one month of treatment with Pentostam (Sodium stibogluconate) local injections at the site of lesions the lesion progressed from ulcer to scar.Conclusion: L. major is a major species causing cutaneous leishmaniasis in Al-Medina Manowra region in Saudi Arabia. The usage of the polymerase chain reaction (PCR) is a useful diagnostic tool and help to identify the causative species.Bangladesh Journal of Medical Science Vol. 12 No. 03 July ’13 Page 325-330 DOI: http://dx.doi.org/10.3329/bjms.v12i3.13189 


Author(s):  
P. B. Notopuro ◽  
J. Nugraha ◽  
H. Notopuro

tuberculosis is a chronic infectious disease which is found in developing and developed country. It is one of community healthproblems which become priority in national and international health programs. Microbiologic examination is used to establish thediagnosis of tuberculosis beside clinical examination and radiologic examination. Conventional microscopic and culture examinationhave many limitation ie: such as for example low sensitivity, specificity and need a lot of time. New Molecular technique gives morevalue in sensitivity, specificity and the time for examination. the aim of this study was to know the diagnostic value of PolymeraseChain Reaction for detection of Mycobacterium tuberculosis in sputum. the sputum was collected from twenty eight patients suspectedtuberculosis based on the clinical and radiological examination. the study was performed from September 2006 until July 2007. Wedid the conventional culture technique as a diagnostic gold standard and molecular technique to detect the Mycobacterium tuberculosisin the sputum. For molecular technique, we used Polymerase Chain Reaction (PCR) with a set of IS6110 region primer which is specificfor the Mycobacterium tuberculosis Complex. the sensitivity of PCR with IS6110 region primer is 100% (very high), specificity is 82.4%(high), positive predictive value is 89.7% and negative predictive value is 100%. there was statistically no significant difference betweenthe result of PCR and conventional culture method. Based on the result, the Polymerase Chain Reaction examination with primer IS6110region primer can be used as the screening tool for tuberculosis infection, while the clinician waits for culture result.


2013 ◽  
Vol 24 (3) ◽  
pp. e69-e74 ◽  
Author(s):  
PD Andrade ◽  
MT Fioravanti ◽  
EBV Anjos ◽  
C De Oliveira ◽  
DM Albuquerque ◽  
...  

BACKGROUND: Human cytomegalovirus is an important cause of morbidity and mortality in immunocompromised patients. Qualitative polymerase chain reaction (PCR) has proven to be a sensitive and effective technique in defining active cytomegalovirus infection, in addition to having low cost and being a useful test for situations in which there is no need for quantification. Real-time PCR has the advantage of quantification; however, the high cost of this methodology makes it impractical for routine use.OBJECTIVE: To apply a nested PCR assay to serum (sPCR) and to evaluate its efficiency to diagnose active cytomegalovirus infection compared with PCR of peripheral blood leukocytes (L-PCR).METHODS: Samples of 37 patients were prospectively evaluated. An internal control was created and applied to sPCR to exclude false-negative results.RESULTS: In total, 21 patients (57%) developed active cytomegalovirus infection. After analyzing the two methods for the diagnosis of active infection, higher sensitivity and negative predictive value of the L-PCR versus sPCR (100% versus 62%), and higher specificity and positive predictive value of sPCR versus L-PCR (81% versus 50% and 72%, respectively) were observed. Discordant results were observed in 11 patients who were L-PCR-positive but sPCR-negative for active cytomegalovirus infection, five of whom developed clinical symptoms of cytomegalovirus. Clinical symptoms were observed in 14 patients, 12 of whom were diagnosed with active infection by nested L-PCR (P=0.007) and seven by nested sPCR (P=0.02). Higher specificity and a positive predictive value for sPCR were observed.CONCLUSION: Nested L-PCR and sPCR were considered to be complementary methods for the diagnosis and management of symptomatic cytomegalovirus infection.


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