Problems encountered in conventional HIV 1/2 Algorithms: lack of necessity for immunoblot assays to confirm repeated ELISA reactive results

Background: The use of conventional (serologically based) HIV 1/2 diagnostic algorithms has become controversial in recent years.Objectives: Sera from patients who underwent verification tests were evaluated because repeated ELISA-reactive results demonstrated a HIV1+HIV2 positive band pattern.Methods: The line immunoassay (LIA) test was used for repeated HIV enzyme immunoassays (EIA)-reactive sera in patients at three centers. The Bio-Rad Geenius™ HIV 1/2 and the HIV-1 RNA tests were used. HIV-1 and RNA HIV-2 were investigated using PCR.Results: LIA was used to evaluate 3,224 out of 10,591 samples with repeated ELISA reactivity (30%). We found that 32 (1%) of the sera, along with HIV1 bands and HIV2 gp36 bands, were positive. Only 28 of the 32 verified serum samples with gp36 bands were repeated, and no gp36 band positivity was detected using the Bio-Rad Geenius™ HIV-1/2 confirmatory assay in these serum samples. The HIV-2 proviral DNAs were also negative. Therefore, we excluded the possibility of HIV1+2 co-infection. All samples from the 32 patients were positive for HIV-1 RNA.Conclusion: Our findings highlight the need to exclude confirmatory tests like the LIA test from the current diagnostic HIV algorithm and replace it with rapid HIV-1 and HIV-2 confirmatory immunochromotographic tests.Keywords: HIV, AIDS, HIV-2

Problems encountered in conventional HIV 1/2 Algorithms: lack of necessity for immunoblot assays to confirm repeated ELISA reactive results

Background: The use of conventional (serologically based) HIV 1/2 diagnostic algorithms has become controversial in recent years. Objectives: Sera from patients who underwent verification tests were evaluated because repeated ELISA-reactive results demonstrated a HIV1+HIV2 positive band pattern. Methods: The line immunoassay (LIA) test was used for repeated HIV enzyme immunoassays (EIA)-reactive sera in patients at three centers. The Bio-Rad Geenius\u2122 HIV 1/2 and the HIV-1 RNA tests were used. HIV-1 and RNA HIV-2 were investigated using PCR. Results: LIA was used to evaluate 3,224 out of 10,591 samples with repeated ELISA reactivity (30%). We found that 32 (1%) of the sera, along with HIV1 bands and HIV2 gp36 bands, were positive. Only 28 of the 32 verified serum samples with gp36 bands were repeated, and no gp36 band positivity was detected using the Bio-Rad Geenius\u2122 HIV-1/2 confirmatory assay in these serum samples. The HIV-2 proviral DNAs were also negative. Therefore, we excluded the possibility of HIV1+2 co-infection. All samples from the 32 patients were positive for HIV-1 RNA. Conclusion: Our findings highlight the need to exclude confirmatory tests like the LIA test from the current diagnostic HIV algorithm and replace it with rapid HIV-1 and HIV-2 confirmatory immunochromotographic tests

Investigation of Cronobacter sakazakii (Enterobacter sakazakii) Presence in Cereal Infant Foods

C. sakazakii is an opportunistic pathogen that may cause serious infections. Infant formulas are frequently reported as the source of infections caused by C. sakazakii. In spite of all of the taken precautions, there are recently published studies related to the isolation of C. sakazakii in formula and small children foods. In this study, we aimed to investigate the presence of C. sakazakii in cereal based infant formulas and complementary foods sold in the markets of Turkish Republic of Northern Cyprus (TRNC). We also aimed to determine the infection risk in these products. This research was carried out between May - December 2017 with the cereal-based continuing formulas and small child complementary foods of the brands offered for sale at T. R. N. C. In a total of 265 samples, including 36 varieties of cereal-based infant formula and 17 varieties of cereal-based infants and small children foods were analysed. Analysis of samples were carried out according to; ISO / TS 22964: 2006 method. C. sakazakii was not detected in any of the study samples. In conclusion, C. sakazakii was not detected in any of the cereal-based foods despite the reported detection of C. sakazakii in most of the microbiological analysis of baby foods in both the world and Turkey

Point Mutations at gyrA and gyrB Genes of Levofloxacin Resistant Helicobacter pylori Strains and Dual Resistance with Clarithromycin

Background: Spontaneous point mutations in genes encoding gyrA/B subunits of DNA gyrase are responsible for fluoroquinolone resistance. We aimed to determine the clarithromycin and levofloxacin resistance phenotypically in H. pylori strains and to investigate the mutations responsible for levofloxacin resistance and the effects of these mutations on dual antibiotic resistance. Methods: A total of 65 H. pylori isolates were included. The E-test method was used for the clarithromycin and le-vofloxacin antimicrobial susceptibility test. Real-time PCR was used to detect the point mutations. Results: Twenty-four (36.9%) of 65 H. pylori strains were phenotypically resistant to clarithromycin and 14 (21.5%) to levofloxacin. The phenotypic levofloxacin resistance rate of strains with Asn87Lys and Asp91Asn mu-tations were significantly higher (gyrA gene) (p < 0.05). The phenotypic levofloxacin resistance rate of strains with Arg484Lys and Asp481Glu mutations were significantly higher (gyrB gene) (p < 0.05). The Asn87Lys mutation in-creased the risk of phenotypes being resistant to levofloxacin 70.156 times and Asp91Asn mutation increased 125,427 times higher. Seven (10.8%) of 65 H. pylori strains showed dual resistance to both levofloxacin and cla-rithromycin. The rate of being dual resistant with A2143G mutation (clarithromycin resistance) was found to be significantly higher (p < 0.05). Conclusions: The Asn87Lys and Asp91Asn mutations in the gyrA gene had a phenotypically enhancing effect on levofloxacin resistance, while the presence of Asp481Glu and Arg484Lys mutations in the gyrB gene did not. The existence of dual resistance was developed with the increase in clarithromycin and levofloxacin resistance rates. (Clin. Lab. 2021;67:2369-2377. DOI: 10.7754/Clin.Lab.2021.210843)Istanbul University-Cerrahpasa Research Fund [45704]This work was supported by the Istanbul University-Cerrahpasa Research Fund under project number 45704.WOS:0007076624000272-s2.0-85117194653PubMed: 3465518