Diagnosis of Bacteriuria and Leukocyturia by Automated Flow Cytometry Compared with Urine Culture▿

Urinary tract infection (UTI) is a widespread disease, and thus, the most common samples tested in diagnostic microbiology laboratories are urine samples. The “gold standard” for diagnosis is still bacterial culture, but a large proportion of samples are negative. Unnecessary culture can be reduced by an effective screening test. We evaluated the performance of a new urine cytometer, the Sysmex UF-1000i (Dasit), on 703 urine samples submitted to our laboratory for culture. We compared bacteria and leukocyte (WBC) counts performed with the Sysmex UF-1000i to CFU-per-milliliter quantification on CPS agar to assess the best cutoff values. Different cutoff values of bacteria/ml and WBC/ml were compared to give the best discrimination. On the basis of the results obtained in this study, we suggest that when the Sysmex UF-1000i analyzer is used as a screening test for UTI the cutoff values should be 65 bacteria/ml and 100 WBC/ml. Diagnostic performance in terms of sensitivity (98.2%), specificity (62.1%), negative predictive value (98.7%), positive predictive value (53.7%), and diagnostic accuracy (73.3%) were satisfactory. Screening with the Sysmex UF-1000i is acceptable for routine use. In our laboratory, we have reduced the number of bacterial cultures by 43%, speeded up their reporting, and decreased the inappropriate use of antibiotics

Genital Chlamydia trachomatis infections

Chlamydia trachomatis (C.t.) infection is one of the most prevalent sexually transmitted disease in Europe and in developed countries. The main biological features and pathogenic mechanisms of C.t. infection are summarized in this review. It usually occurs without symptoms and often goes undiagnosed. If untreated, it can cause severe consequences for women, including pelvic inflammatory disease (PID), ectopic pregnancy and tubal infertility. Several studies have found that Chlamydia is more common among young women <25 years old, with multiple sexual partners within six months and non protected intercourses. Because re-infection rates are high, complications may be reduced if partners are treated and women re-tested. This paper emphasizes the importance of counselling and prevention programs and underlines that selective screening of high-risk population remains an essential component of C.t. control. In the last years, the detection of C.t. infection has been improved in sensitivity and specificity.We describe the main diagnostic techniques, from culture, enzyme immunoassay (EIA), direct fluorescent-antibody assay (DFA) to the new DNA-based test systems. Actually, NAATs (nucleic acid amplification tests) are regarded as the gold standard diagnostic techniques for chlamydial infections