Correlation of Treponemal Chemiluminescent Microparticle Immunoassay Screening Test Signal Strength Values With Reactivity of Confirmatory Testing.

BACKGROUND: Automated chemiluminescent microparticle immunoassays (CMIAs) are the most common first step at high-volume laboratories for syphilis screening. If the initial screening test is reactive, 1 more treponemal test is required, resulting in increased cost. In this multicenter study, we aimed to determine the correlation between the CMIA signal-to-cutoff ratio (S/Co) and the confirmatory tests to reduce unnecessary confirmatory testing. METHODS: Eight hospitals from 5 provinces participated in this study. All laboratories used Architect Syphilis TP CMIA (Abbott Diagnostics, Abbott Park, IL) for initial screening. Treponema pallidum hemagglutination (TPHA), rapid plasma reagin (RPR), and fluorescent treponemal antibody absorption (FTA-ABS) were used as confirmatory tests according to the reverse or European Centre for Disease Prevention and Control algorithms. A receiver operating characteristic analysis was used to determine the optimal S/Co ratio to predict the confirmation results. RESULTS: We evaluated 129,346 serum samples screened by CMIA between January 2018 and December 2020. A total of 2468 samples were reactive; 2247 (91%) of them were confirmed to be positive and 221 (9%) were negative. Of the 2468 reactive specimens, 1747 (70.8%) had an S/Co ratio ≥10.4. When the S/Co ratios were ≥7.2 and ≥10.4, the specificity values were determined to be 95% and 100%, respectively. In a subgroup of 75 CMIA-positive patients, FTA-ABS was performed and 62 were positive. Among these FTA-ABS-positive patients, 24 had an S/Co ratio <10.4, and negative TPHA and RPR. CONCLUSIONS: We propose a potentially cost-effective reverse screening algorithm with a treponemal CMIA S/Co ratio ≥10.4, obviating the need for secondary treponemal testing in about 71% of the screening-reactive samples. This would substantially reduce the confirmatory testing volume and laboratory expenses. However, in high-risk group patients with CMIA positive results, S/Co ratio <10.4, and negative TPHA and RPR, FTA-ABS may be used for confirmation.

[Results of a multicenter study investigating plasmid mediated colistin resistance genes (mcr-1 and mcr-2) in clinical Enterobacteriaceae isolates from Turkey]. / Ülkemizde klinik Enterobacteriaceae izolatlarinda plazmit aracili kolistin direnç genlerini (mcr-1 ve mcr-2) arastiran çok merkezli çalismaya ait sonuçlar.

Colistin is a polymyxin antibiotic which is considered as one of the last line agents against infections due to multidrug resistant or carbapenem resistant gram-negative pathogens. Colistin resistance is associated with chromosomal alterations which can usually cause mutations in genes coding specific two component regulator systems. The first plasmid-mediated colistin resistance gene, mcr-1 was described in Escherichia coli and Klebsiella pneumoniae isolates in December 2015 and followed by another plasmid-mediated colistin resistance gene mcr-2 in 2016. The rapid and interspecies dissemination of plasmid-mediated resistance mechanisms through horizontal gene transfer, have made these genes considerably threatening. After the first reports, although mcr-1/mcr-2 producing Enterobacteriaceae isolates have been reported from many countries, there have been no reports from Turkey. Thus, the aim of this study was to investigate the presence of mcr-1/mcr-2 in clinical Enterobacteriaceae isolates from different parts of our country. A total of 329 Enterobacteriaceae isolates from 22 laboratories were collected which were isolated between March, 2015 and February, 2016. mcr-1/mcr-2 were investigated by polymerase chain reaction during February-March, 2016. Two hundred and seventeen of Klebsiella pneumoniae (66%), 75 of Salmonella spp. (22.8%), 31 of Esherichia coli (9.4%), 3 of Enterobacter cloacae (0.9%), 2 of Klebsiella oxytoca (0.6%) and 1 of Enterobacter aerogenes (0.3%) isolates were included to the study. Agarose gel electrophoresis results of PCR studies have shown expected band sizes for positive control isolates as 309 bp for mcr-1 and 567 bp for mcr-2. However, the presence of mcr-1/mcr-2 genes was not detected among the tested study isolates of Enterobacteriaceae. Although mcr-1/mcr-2 were not detected in our study isolates, it is highly important to understand the mechanism of resistance dissemination and determine the resistant isolates by considering that colistin is a last-line antibiotic against infections of multidrug or carbapenem resistant gram-negative bacteria. Thus, it is suggested that these mechanisms should be followed-up in both clinical and non-clinical (e.g. isolates from food animals, raw meats and environment) isolates of special populations.

SEROPREVALENCE OF RUBELLA ANTIBODIES AMONG TURKISH AND FOREIGN WOMEN IN TURKEY.

The aims of this study were to determine seroprevalence of rubella antibodies among Turkish and foreign women living in Turkey and to estimate percent women susceptible to rubella infection. This retrospective study was conducted among 970 women (816 Turks) attending gynecology and obstetrics outpatient clinics. Serum samples were tested for anti-rubella IgG and IgM by chemiluminescent microparticle immunoassay. Eighty-eight percent of the subjects were positive only for anti-rubella IgG indicating immunity to rubella infection, none for only anti-rubella IgM and 1.5% for both anti-rubella IgM and IgG, the latter having a high avidity of anti-rubella IgG signifying a previous infection. Anti-rubella IgG seropositivity rate alone for Turkish women is 86.1%, significantly higher than that for foreign women. A significant association between age and seropositivity was found only for the age group of 15-20 years among both Turkish and foreign women. Anti-rubella IgG seropositivity rate of pregnant women increased with increasing age from 10.7% (at 15-20 years old) to 85.5% (at 36-40 years old). Among non-pregnant women, both anti-rubella IgM and IgG seronegativity rates were significantly higher in the age group of 31-35 years than the other age groups. Our results indicate that all pregnant women in Turkey should routinely be screened for anti-rubella IgM and IgG at antenatal period. Evaluation of susceptibility of women in reproductive age to rubella infection is important to setup a strategy for preventing antenatal rubella through vaccination of non-immune women throughout the country.

Comparison of a New and Rapid Method: Brucella Coombs Gel Test With Other Diagnostic Tests.

BACKGROUND: The aim of this study was to detect reliability of Brucella Coombs gel test (BCGT) by comparing with with ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination methods in serological diagnosis of brucellosis. METHODS: Brucella Coombs gel test (BCGT), Brucella ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination tests of 78 patients with presumptive diagnosis of brucellosis which were sent to Microbiology Laboratory of Konya Numune Hospital from various regions of Konya were studied. RESULTS: Of 78 patients with ELISA IgG and IgM, STA, BICA and BCGT; 26, 21, 10, 12 and 12 were positive. When compared with BICA, the sensitivity and specifity of BCGT were 100% and 100%, respectively. CONCLUSION: According to results BCGT can be used as a diagnostic test in routine laboratories after more comprehensive studies in control groups and patients.

The seroprevalence of both hepatitis B and hepatitis C at the first-step health organizations and the difference between the urban and rural areas.

BACKGROUND: Hepatitis B virus (HBV) and hepatitis C virus (HCV) are very important infectious agents for public health. The aim of this retrospective study was to assess the seroprevalence of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs) and anti-HCV test results of patients who admitted to first-step health organizations in central and peripheral districts of Konya, the central region of Turkey during the period 2005-2010. METHODS: In this study, HBsAg, anti-HBs and anti-HCV screening test results of patients who admitted to first-step health organizations in Konya during the period 2005-2010 were retrospectively investigated from the laboratory records. This study was approved by the Konya Health Directorate. All screening tests were performed on the automatic third-generation enzyme-linked immunosorbent assay (MEIA). This immunoassay method was carried out according to the instructions of the manufacturer. Borderline and positive results were retested. RESULTS: Konya is the largest city of Turkey in terms of surface area and one of the economically developed cities. For HBsAg, anti-HBs and anti-HCV screening, whole test results of 5 years are given in Table 1 and Figure 1. The differences between the urban and rural for HBsAg (p = 0.062 > 0.05) and anti-HCV(p = 0.874 > 0.05) were not statistically significant. Among the markers only for anti-HBs, the difference between the urban and rural was statistically significant (P = 0.042 < 0.05). Of them, 4.15 % were positive for HBsAg, 36.46 % were positive for anti-HBs and 1.16 % were positive for anti-HCV. CONCLUSION: In this study, Konya has been evaluated as two regions: central and peripheral. Our study showed us that distribution of the diseases vary from one region to another. We consider that difference in social diversity is one of the factors. These infections are major health problems. So the results of immunodiagnostic tests for HBsAg, anti-HBs and anti-HCV will be useful for guiding control actions and for new preventive strategies.

Relationship between the GOLD combined COPD assessment staging system and bacterial isolation.

BACKGROUND: Acute exacerbations, which are a significant cause of mortality and morbidity, adversely affect chronic obstructive pulmonary disease (COPD) prognosis by accelerating loss of lung function. It is important to know the microorganisms that commonly cause exacerbations in the patient groups classified according to clinical and functional characteristics for fast and accurate treatment of acute exacerbations. OBJECTIVES: The last Global Initiative for Chronic Obstructive Lung Disease (GOLD) publication recommended a new staging system containing obstruction degree, frequency of exacerbations, and quality of life questionnaires. This study is designed to analyze the relationship between the bacteria isolated in acute exacerbations and new GOLD stages. METHODS: Potentially pathogenic bacteria (PPB) isolation with culture and polymerase chain reaction methods were obtained from 114 acute exacerbation COPD patients, classified into A, B, C, and D groups by analyzing the forced expiratory volume in 1 second (FEV1) value, COPD Assessment Test (CAT) score, and exacerbation frequency according to the new GOLD staging system. RESULTS: There was a significant correlation between exacerbation frequency and PPB isolation (P=0.002). There was no relationship between GOLD stage, FEV1, and CAT score with PPB isolation. The isolated bacteria diversity and mixed infection frequency were higher in the GOLD stage D group. Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter baumannii were isolated only from D group patients. CONCLUSION: Bacterial infection may cause an acute exacerbation equally in each stage for COPD. The difference in bacterial etiology is more related to exacerbation frequency than FEV1 and CAT scores for an acute exacerbation. Determining exacerbation frequency is significant for treatment success in empirical antibiotic selection.

[Investigation of the presence of Helicobacter pylori by different methods in patients with dyspeptic complaints]. / Dispeptik yakinmalari olan hastalarda Helicobacter pylori varliginin farkli yöntemlerle arastirilmasi.

Helicobacter pylori infections which are common worldwide may be a risk factor for gastritis, gastric and duodenal ulcers, gastric adenocarcinoma and mucosa-associated lymphoid tissue (MALT) lymphomas. For the detection of H. pylori, invasive methods such as culture, histopathology and rapid urease tests which require endoscopy and gastric biopsy specimen and non-invasive methods (not requiring endoscopy) such as urea breath test, stool antigen test (H. pylori stool antigen; HpSA) and serology are used. The aim of this study was to investigate the presence of H. pylori in patients with dyspeptic complaints, by rapid urease test, HpSA test, culture and histopathology and to evaluate the diagnostic performance of HpSA test. A total of 103 dyspeptic patients who were admitted to Selcuk University Meram Medical Faculty Gastroenterology Clinic and undergone gastroduodenal endoscopy between January 2005 and December 2006, were included to the study. All the specimens were cultivated, however, urease activity was tested in 98 of the patients, histopathological examination in 76 and HpSA test in 86 of the patients. H. pylori was isolated in 38.8% (40/103) of the specimens by culture. H. pylori was positive in 38.2% (29/76) of the specimens by histopathology, in 86.7% (85/98) by urease test, and in 44.2% (38/86) by HpSA test. The sensitivity and specificity values of the tests when culture was taken as the gold standard, were; 97.5% and 20.7% for urease test, 75% and 82.6% for HpSA test and 72.5% and 100% for histopathology, respectively. In conclusion, HpSA method could be applied as a screening test for H. pylori diagnosis in case endoscopy could not be performed. However, if invasive methods were to be performed, the diagnosis should be confirmed by a more sensitive and specific test such as culture and histopathology.