Evaluation of a PCR assay to detect Enterococcus faecalis in blood and determine glycopeptides resistance genes: van A and van B

Bacteremia due to Enterococcus faecalis is usually caused by strains resistant to most antibiotics. Effective management of the disease is dependent on rapid detection and characterization of the bacteria, and determination its sensitivity pattern to antimicrobial drugs. The aim of this study was to investigate a more rapid and reliable assay for simultaneous diagnosis of enterococcal bacteremia and its sensitivity pattern to antimicrobial drugs. Several bacterial suspensions with different content of two standard strains of Enterococcus faecalis resistant to vancomycin were used for inoculation to defibrinated sheep blood samples. PCR and routine assay was performed on all blood samples with different bacterial content. Routine assay and PCR for all inoculated blood samples with >/= 5 cfu/ml was positive. Mean time for PCR and routine assays was 10 hours and 5 days, respectively. PCR is a more rapid and sensitive assay for simultaneous detection and characterization for Enterococcus faecalis, and determination of its sensitivity pattern to vancomycin

[Microbiological study and antimicrobial susceptibilities of brucella isolates in serologic diagnosed cases]

Brucellosis is a zoonotic disease with worldwide distribution that is endemic in Iran. Worldwide, brucellosis remains a major cause of morbidity in humans and domesticated animals. The disease has a wide spectrum of clinical manifestation and can affect a variety of organs and systems. This study focused on blood culture of serologic diagnosed brucellosis and antimicrobial susceptibility test. In this cross sectional study, microbiologic survey was done on a total of 30 serum samples with STA titer of 1:160 or greater and 2ME titer of 1:40 or greater, which were presumptive for brucellosis. Blood cultures were done by lysis centrifugation and antimicrobial susceptibility test, against 9 antimicrobial agents by disk method. The data was analyzed by stata V8.0 software. At the end this study, the blood culture isolation rate was 23.3% [7 cases out of 30 patients] and all of the isolates were brucella melitensis. Antimicrobial susceptibility tests showed high in vitro activity of ofloxacin, ciprofloxacin and doxycycline and also, low in vitro activity of streptomycin and cotrimoxazole. Brucellosis is endemic in Iran. Brucella melitensis was the most common strain of brucella in our patients. Except cotrimoxazole and streptomycin, high in vitro activity was found with other antibrucella agents, especially with ofloxacin, ciprofloxacin and doxycycline

[Evaluation of latex agglutination test for diagnosis of leptospirosis using native strains]

Leptospirosis is a common zoonosis throughout the world and common in the flat area of Guilan, Iran, with seasonal incidence, especially in rice farmers. Clinical diagnosis of leptospirosis is difficult, because its symptoms are similar to several acute infective diseases. Serological assays are important in diagnosis of the disease and microscopic agglutination test [MAT] is a gold standard, however, it is not a routine test in diagnostic laboratories. Thus, a simple and reliable test is a necessity. In this study, we evaluated a latex agglutination test using native strains of leptospires. A number of 98 positive cases and 54 negative cases which were screened by MAT, along with 30 sera of other diseases as control samples, were examined by latex agglutination test, using an antigenic suspension [whole antigen], which was extracted from 4 common native strains. False positive and false negative rate were 15 and 12 consequently. Sensivity, specificity, positive predictive value, negative predictive value, and accuracy were 89.0%, 84.5%, 86.7%, 87.2%, and 87.0% respectively. Regarding the considerable rate of sensivity and specificity of the test which is compatible to other performed studies, in addition to the simple performance test, does not need a complex laboratory facility, which may also be carried out in rural regions, therefore, this test is valuable for primary screening

[Seroprevalence of Chlamydia pneumonia in patients with myocardial infarction]

Several predisposing and risk factors are introduced as main causes of coronary atherosclerosis which is the main cause of myocardial infarction [MI]. In recent years, chronic and persistent infections are considered as such factors. This study is basically on determination of seropositivity to Chlamydia pneumonia to reveal the role of acute and chronic infections due to these bacteria as a risk factor for MI. 273 serum samples from MI patients and 109 samples from control group were examined by using commercial quantitative ELISA kits to measure specific anti Chlamydia pneumonia antibodies [IgM and IgG]. Two groups were matched for age and sex. IgM titers [ELISA] were negative in all patients and control cases, indicating lack of acute Chlamydial infection, but IgG titers were positive in 273 patients [94.4%], [mean average titer: 108 RU/ml] and in 109 control cases [84.4%] [mean average of titer: 61.9 RU/ml]. We found no significant relationship between seropositivity to Chlamydia pneumonia antibodies [lgG] with MI [P=0. 104]. In this study, no significant relationship was observed between serpositivity to Chlamydia pneumonia and subsequent incidence of MI. It seems that a large scale serological study with a diagnostic molecular methods for detection of genome in biopsy tissue of atherosclerotic coronary artery will be more helpful to reveal the expected relationship

Epidemiologic assessment of Leptospira serotypes in Caspian littoral

Leptospirosis is a widespread zoonosis in the world with more prevalence in tropical and subtropical regions. The disease is very common in flat area of Gilan, northern Iran, where the climate is humid and temperate and rice farming is main agricultural activity in rural areas. We performed this study in 2004 by taking blood samples from 465 hospitalized patients who were suspected of leptospirosis based on their clinical presentation, to find positive cases and analysis their signs, symptoms, and epidemiological data, and also to determine the most common clinical features of the disease in the area. All sera were examined by microscopic agglutination test. Renal failure was most common symptoms [4.5%]. Icterhaemorrhagia had highest titers in 57.0% of patients. In Gilan province, some of the farmers get leptospirosis each year near the end of spring and summer at the time of rice harvesting. Better recognition of the disease and diagnosing it at proper time can improve the quality of life and health state of the farmers

[Evaluation an in-house IgM-ELISA for the diagnosis of human leptospirosis]

Leptospirosisis a very common zoonosis in the world. Culture is low sensitive with high rate false negative. So, serological assays are best alternative way for its diagnosis. Microscopic agglutination test [MAT] is gold standard but performing it requires a panel of some standard strains and need periodic subculturing of them, and also requires double sera with at least two weeks interval to investigate seroconversion. Furthermore, other serological methods should be investigated. The aim of this study was to evaluate an in-house IgM-ELISA developed by using antigen extracted from endemic isolates. 14 endemic isolates belonged to the serogroups: Icterohaemorrahgia, Pomona, Hardjo, and Gripotyphosa, were inoculated in EMJH to take well grown cultures. Whole antigen was extracted from each culture by Freezing-Thawing method in distilled water. Same amount of extraction of each culture with same OD number in 550nm were mixed together and were used for coating Elisa plates. Antihuman IgM conjugated with alkaline phosphatase were used in this assay. We used a commercial quantitative IgM-ELISA [SERION ELISA classic] for cut off determination. MAT was used for confirmation positive and negative cases. Sera with titer >/= 1:100 in MAT and positive criteria in commercial quantitative IgM-ELISA were considered as positive cases. 98 positive cases and 54 negative cases were chosen by screening 200 sera of patients suspected to leptospirosis by using MAT and commercial quantitative IgM-ELISA. We also used 30 sera of patients affected by hepatitis B, salmonelosis, and brucellosis as control cases. 88 of 98 positive cases were positive [false negative=10], 1 of 54 negative and all control case were negative [false positive =1] in the test. Sensitivity, specificity, PPV, NPV, and accuracy of the test were evaluated :99.0%, 89.1%, 90.75, 98.8%, and 94.25, respectively. ELISA for measuring specific IgM to leptospires antigen[s] could be a good alternative to MAT, which is not a routine diagnostic assay to perform in clinical diagnostic laboratories and only is reliable when there is paired sera. Sensitivity and specificity of the assay is dependent to several factors, especially to the type of antigen coated on plates, quality of assay materials, and also to the time of sampling. Sera of days >/= 6 of the disease has enough antibodies to measure and a common antigen extracted from several common pathogenic leptospires, especially from endemic isolates, could be more helpful to increase accuracy of the assay

Leptospirosis in flat area of Guilan province, Iran, in 2005

Leptospirosis is a widespread zoonosis in the world and is more prevalent in tropical and temperate regions. Flat area of Guilan province is the only endemic area of human leptospirosis in Iran. In 2005, a study was done to investigate the incidence of leptospirosis in the area. We collected blood samples from patients who attended three big general hospitals in the region with clinical presentation consistent with leptospirosis. All sera were examined by a quantitative Igm-Elisa and also by the Microscopic Agglutination Test [MAT] by using 18 standard strains. Sera which were positive in quantitative 19m-Elisa and had titers =160 against at least one pathogenic serovar in mat, were regarded as positive cases [170 from 482]. Analysis of demographic and epidemiological data of positive cases showed that leptospirosis is a disease of predominantly males [62.50%], occurring in high incidence in villagers [89.50%], mainly during the warm season [100%] and notably in September [42.90%]. In addition it is an occupational disease affecting mainly rice field workers [about 90%]