Biochemical Test Kits Research Articles

Prevalence of yeasts in saliva and root canals of teeth associated with apical periodontitis.

To determine: (i) the relative prevalence and diversity of yeasts in salivary and root canal samples from the same patients; and (ii) the clinical factors associated with their presence in saliva and root canals. Sixty root canal samples from teeth associated apical periodontitis and the corresponding whole unstimulated saliva samples were obtained from 55 patients. The medical history including antibiotic therapy and clinical/radiographic data on the teeth were recorded. The samples were serially diluted and cultured on yeast & fungi-selective sabouraud dextrose agar. Isolates were characterized and speciated by the germ tube formation test, hyphal morphology and a commercial biochemical test kit (Rapid ID32C(R) system). Twenty-three yeast isolates were recovered from 19 saliva samples and eight isolates from six root canal samples. Candida albicans (17/23 & 3/8) and Rodotorula mucilaginosa (2/23 & 4/8) were the most prevalent isolates from saliva and root canal samples. It was significantly (13.8 times) more probable that yeasts would be recovered from root canals when they were also present in the saliva (P = 0.021). The effect of coronal restoration leakage (P = 0.08) and previous root canal treatment (P = 0.123) were equivocal. The history of antibiotic therapy had no association with the presence of yeasts in saliva (OR = 1.1). Yeasts occurred relatively infrequently (10%) in root canals. Their presence in root canals was significantly associated with their presence in saliva. The role of yeasts in the initiation and perpetuation of periapical disease remains to be determined.

Evaluation of diagnostic methods of re-emerging malaria in Korean patients.

Malaria is one of the most important parasitic diseases especially in tropical areas. Over 300 million people are affected and the condition causes 1-3 million deaths each year. It is transmitted by the bite of infected Anopheles mosquitoes. Although Korea was declared to be free of Malaria by the WHO in 1979, malaria re-emergence has been apparent since 1993 amongst soldiers located near the De-Militarized Zone (DMZ) in the northern part of the country. Conventional microscopic examination of thin and thick blood films demonstrates the presence of the parasite and thus this method has been used to confirm the diagnosis of malaria, but it is a labor-intensive procedure and relies upon subjective interpretation. To overcome these limitations, fast and reliable methods for malaria detection have been recently introduced. In this study, we compared three kinds of antibody detection kits and one biochemical test kit that determines the presence of Plasmodium lactate dehydrogenase (pLDH) with conventional peripheral blood smears. The antibody detection methods examined were, two rapid test pack format methods and a single microplate format enzyme-linked immunosorbent assay (ELISA) kit, as manufactured by Korean companies. The sensitivities of the three commercial antibody detection kits in the early stage of malaria were 70.8%, 77.4%, and 63.6%, their corresponding specificities 90.5%, 91.8%, and 80.9%, and their accuracies 87.6%, 87.0%, and 76.7%. The sensitivity and specificity of the pLDH assay were 100% apiece and the results were in 100% concordance with the microscopy of thick blood films. Thus, the pLDH assay may be used as an alternative for conventional microscopic blood film examination, especially in emergency situations when prompt treatment is necessary.

The influence of local plant growth conditions on non-fastidious bacterial contamination of meristem-tips ofHydrangea culturedin vitro

A high incidence ofin vitro bacterial contamination (69%) has been detected in meristem-tip explants ofHydrangea from widely differing locations in Ireland and the UK. The bacteria were characterised by API 20E biochemical test kits and by fatty acid profile analysis. The results obtained from the different methods were compatible and anomalies were explicable in terms of the limitations of the respective methods. The majority of the isolates were environmental or animal-associated bacteria with clusters ofEnterobacter isolates in Dublin, and ofEscherichia coli in the main Cork location. A cluster of Pseudomonads was detected in the Derby (UK) plants. The main association was between the location and the contaminant clusters. The main finding was that the nature of organic soil amendments may influence inoculum for the contamination of plants and the conclusion was that fertilisation with organic materials should be avoided in the preparation of plants for micropropagation.

METHODS FOR THE DETECTION OF FOODBORNE LISTERIA MONOCYTOGENES IN THE U.S.

ABSTRACT A review of methods for the isolation and detection of Listeria monocytogenes used in the United States is presented. Methods reviewed include the cold enrichment technique, the FDA Method, the USDA Method, and two rapid techniques, the Listeria‐Tek enzyme‐linked immunosorbent assay and the Gene‐Trak Listeria Assay. Comparisons of new rapid biochemical test kits, the MICRO‐ID LISTERIA System, API Listeria, and the Rosco system vs. conventional tests of identification are also reviewed. Contemporary isolation methods detect all Listeria species so confirmation of L. monocytogenes is still necessary after isolation. The USDA method is the most practical of the cultural methods due to the rapid reporting of negative samples. Rapid methods (Listeria‐Tek and the Gene‐Trak Listeria Assay) are faster and more objective than cultural procedures but still depend on sample enrichment for detection of Listeria. These rapid techniques are best utilized when screening large numbers of food samples. All the rapid biochemical test kits reviewed provide fast reliable identification of Listeria species when compared to classical techniques. However, the API Listeria system identifies the test strains without a complementary CAMP test. Refinements are still needed in both cultural and rapid methods. Future Listeria methodology must emphasize molecular techniques not requiring enrichment which would be both rapid and specific for L. monocytogenes.

Identifying Escherichia Species With Biochemical Test Kits and Standard Bacteriological Tests

Two commercially available biochemical test systems were evaluated for their ability to accurately identify species of the genus Escherichia. Three laboratories participated in the study. The test kits did not always correctly identify species of Escherichia, but only once was an isolate misidentified as Escherichia coli. These results and the reactions of the isolates on media normally used for drinking water analysis are discussed.

Vergleich von API-10S und Minitek mit konventioneller Bunter Reihe

2 biochemical test-kits, API-10S and MINITEK, and conventional biochemical tests were used in parallel for testing 292 strains of the family Enterobacteriaceae. The same 10 biochemical tests were performed in all three systems. In addition the Voges-Proskauer reaction was tested in the conventional and the Minitek-system. The individual biochemical testreactions and diagnoses were compared. An overall average of tests indicated an agreement of 92.6% (Tab. 2). Urease-activity and citrate-utilisation showed the lowest agreement (70.5 and 74.3% respectively). 93.4% of the diagnose obtained with API- and 96.2% of those with MINITEK were identical to the diagnosis obtained by the conventional method. The Voges-Proskauer reaction was found to be more reliable for correct identification than the citrate-utilisation which - inspite of its very low agreement (Tab. 3) - has not influenced the diagnoses.