Is the Second Treponemal Test Necessary in the Reverse Algorithm for the Diagnosis of Syphilis?

BACKGROUND: This study was performed to investigate the necessity of the second treponemal test and to evaluate the diagnostic performance of the first treponemal test in the reverse algorithm of syphilis diagnosis. METHODS: Abbott Architect Syphilis TP assay, a chemiluminescence immunoassay (CIA), was used as the first step treponemal test. Treponema pallidum haemagglutination assay (TPHA) test results of reactive samples from the first test were recorded. TPHA test result was considered as confirmatory. TPHA test results were grouped according to their Abbott Architect Syphilis TP assay results and they were compared with Mann-Whitney U test. For Abbott Architect Syphilis TP assay, a cutoff value with 100% specificity was determined via a ROC curve analysis which would render TPHA test unnecessary. RESULTS: Out of 146,800 samples 2,646 were reactive in the first step. Of those, 2,002 had a TPHA test result. Of the 2,002 TPHA tests, 1,706 were positive and 296 were negative. TPHA positive and negative groups have significantly different CIA signal/cutoff values. Using a ROC curve built for evaluation of the first-step test, the maximum Youden's index value was found as 5.26. If this value would be accepted as cutoff, it would have a specificity of 85%. The specificity of 100% can be reached if a new cutoff value is set to 27.83. CONCLUSIONS: Calculated cutoff value with 100% specificity is not practically applicable. It achieves saving of TPHA test in only six percent of reactive samples. Architect Syphilis TP assay is advantageous in large laboratories but is not enough to lead diagnosis without a second treponemal assay. Therefore it was decided to continue the reverse algorithm with dual treponemal assays.

Genotypic characterization of Pseudomonas aeruginosa isolates from Turkish children with cystic fibrosis.

Objective: To identify epidemic and other transmissible Pseudomonas aeruginosa strains, genotypic analyses are required. The aim of this study was to assess the distribution of P. aeruginosa strains within the Turkish pediatric cystic fibrosis (CF) clinic population. Methods: Eighteen patients attending the pediatric CF clinic of Cerrahpasa Medical Faculty were investigated in the study. Throat swab and/or sputum samples were taken from each patient at 3-month intervals. The isolates of patients were analyzed by pulsed-field gel electrophoresis (PFGE). The intra- and interpatient genotypic heterogeneity of isolates was examined to determine the clonal isolates of P. aeruginosa within the cohort. Results: A total of 108 clinical isolates of P. aeruginosa were obtained from 18 patients between May 2013 and May 2014. The pulsotypes of the first patient's isolates could not be obtained by PFGE. From the remaining 17 patients and 101 isolates, 55 distinct pulsotypes were detected. The number of pulsotypes observed in more than one patient (minor clonal strains, cluster strains) was 8 (14.5%), and one of them colonized three patients. However, none of them was detected in more than three patients. These pulsotypes were composed of 20 isolates. In addition, with the PFGE analysis of 81 isolates, we detected 47 (85.6%) pulsotypes, which belonged to only one patient. Over different periods of this study, only 2 (11.8%) patients were colonized with the same pulsotype. Conclusion: Our study indicates that there was considerable genomic diversity among the P. aeruginosa isolates in our clinic. The presence of shared pulsotypes supports cross-transmission between patients.

[Surveillance of resistance in the intensive care units using a cumulative antibiogram]. / Yogun bakim ünitelerinde kümülatif antibiyogram ile antibiyotik direncinin izlenmesi.

Empiric treatment with broad-spectrum antibiotics exerts condensed pressure in intensive care units (ICUs) for the selection of multidrug-resistant bacteria. Multidrug-resistant gram-negative bacteria became the focus of interest owing to limited treatment options and negative effects on patient survival. Cumulative antibiograms can guide selection of correct empiric treatment, de-escalation treatment according to antibiogram results and development of policies in fight against antibiotic resistance. In this study, we aimed to determine the antibiotic resistance rates of gram-negative bacilli in the intensive care units of the public hospitals in the region where we are connected by using the cumulative antibiogram result and to show the change of resistance over the years and to determine whether there is any difference between the hospitals. Gram-negative bacilli were isolated from ICUs of state hospitals in the second Istanbul State Hospitals Association area during 2014-2016. Isolates were identified using Vitek MS (bioMérieux, France) system and tested for antibiotic susceptibility with Vitek 2 (bioMérieux, France) system according to the Clinical and Laboratory Standards Institute (CLSI) criteria followed during those years. Cumulative antibiogram reports for these strains were prepared according to the CLSI M39-A4 guide. Gram-negative bacilli were divided into three groups: non-fermentative, urinary enteric, and non-urinary enteric bacilli. Total number of strains isolated during three years from these groups were 2626, 1390 and 2011, respectively. Annual trends of susceptibility during the aforementioned years were evaluated. Hospitals were also classified into five groups and differences were evaluated in the susceptibility profiles of these hospitals. Among the non-fermentative bacilli, Acinetobacter baumannii complex was the most commonly isolated species and the most resistant bacteria against antibiotics. The susceptibility rates of A.baumannii complex against the beta-lactam group of antibiotics were < 10%. Colistin susceptibility rates of A.baumannii complex and Pseudomonas aeruginosa isolates were over 98%. Among the non-urinary enteric bacilli, K.pneumoniae was the most commonly isolated species displaying maximum antibiotic resistance. Susceptibility rates for colistin, which is the last resort for treating resistant gram-negative bacteria, ranged between 73% and 80%. Escherichia coli, which was the second most common isolated species among non-urinary bacilli, had susceptibility rates over 90% to carbapenems along with colistin and tigecycline. Although E.coli was the most commonly isolated species among urinary enteric bacilli, K.pneumoniae and Proteus mirabilis were the most resistant isolates. A statistically significant decrease in susceptibility rates against all antibiotics was observed in P.mirabilis isolates between the years 2015-2016. Carbapenem susceptibility rates decreased below 70%. E.coli, Serratia spp., and Stenotrophomonas maltophilia had similar susceptibility profiles among different hospitals, indicating homogenous distribution, whereas other species had different profiles, indicating a more heterogenic distribution, among hospitals. The reports of this study were generated according to a standard guide and they clearly revealed the seriousness of antibiotic resistance in our region which represents approximately one-fourth area of Istanbul. When all the results were considered, best empiric treatment option for enteric bacilli except K.pneumoniae was carbapenems. For K.pneumoniae infections there is no reliable choice other than colistin but a de-escalation treatment can be planned according to antibiogram results. Similarly colistin is the first choice in empiric treatment of infecitons due to non-enteric bacilli. However, the heterogeneity of the susceptibility profile observed in the hospitals, which are geographically close to each other, indicated the difference in the flora of the intensive care unit of hospitals. It would be appropriate to prepare cumulative antibiogram reports similar to those in the present study, to prevent complications, reduce costs and improve patient prognosis in the intensive care units of hospitals and these reports should become part of the infection control policies applied in hospitals.

Isolation rates and antibiotic susceptibilities of different Enterobacteriaceae species as urinary tract infection agents in Turkey: a systematic review.

BACKGROUND/AIM: In Turkey, few systematic reviews have analyzed the results of studies on the isolation rates of urinary tract infection agents and their antibiotic susceptibilities. This review was done to fill this gap and enable the correct application of guideline-based medical therapy by determining the isolation rates and antibiotic susceptibilities of different Enterobacteriaceae species in Turkey. MATERIALS AND METHODS: Relevant studies found from various databases with the help of previously specified search strategies were examined and eliminated according to eligibility criteria. The remaining 22 studies were included in this systematic review. RESULTS: Escherichia coli was the most frequently isolated species among all agents in both in- and outpatient settings. Only the antibiotic susceptibility data of E. coli could be analyzed because among the 22 studies only E. coli had adequate antibiotic susceptibility data to be analyzed. The calculated resistance rates of the most frequently preferred antibiotics (trimethoprim/sulfamethoxazole, ciprofloxacin, and ceftriaxone) were 46%, 32%, and 19% for outpatients and 54%, 48%, and 28% for inpatients, respectively. CONCLUSION: The resistance profiles of commonly used antimicrobial agents are much higher than the thresholds set by international guidelines. Hence, treatment algorithms for urinary tract infections should be designed according to Turkey's antimicrobial resistance patterns.