Microbiological diagnosis of gonorrhoea

Laboratory Capacity for Antimicrobial Susceptibility Surveillance of Neisseria gonorrhoeae-District of Columbia, 2007-2012

BACKGROUND

In the District of Columbia (DC), Neisseria gonorrhoeae (gonorrhea) infections accounted for more than 25% of 9321 incident sexually transmitted infections reported in 2011; untreated infections can lead to reproductive complications and a higher risk for HIV transmission. In DC, limited capacity to measure the prevalence of antibiotic-resistant N. gonorrhoeae is available; culture-based antibiotic susceptibility testing (AST) is needed to monitor antimicrobial resistance. We examined the capacity of laboratories that report to the DC Department of Health to perform AST for ongoing surveillance of antibiotic-resistant N. gonorrhoeae and to identify suspected treatment failures.

METHODS

We created a survey about diagnostic methods for gonorrhea testing and identified 33 laboratories that reported gonorrhea results to Department of Health in 2007 to 2012. Laboratories were assessed for use of bacterial culture or nucleic acid amplification testing (NAAT) for gonorrhea testing, prevalence of AST on gonorrhea-positive cultures, and types of antibiotics tested during AST. We estimated the prevalence of laboratory practices on the basis of self-report by staff.

RESULTS

Nineteen (58%) laboratories completed the survey, representing 92% of the gonorrhea reporting. Seventeen (89%) of 19 laboratories conducted testing by culture; only 6 (35%) performed AST; 79% performed NAAT. Barriers to AST included longer completion times and limited number of provider requests for AST. Commercial laboratories (32%) were more likely to conduct both culture and NAAT, compared with health care facilities (11%).

CONCLUSIONS

We report a low prevalence of laboratories performing AST because of multiple barriers. State-specific strategies addressing these barriers are needed to improve detection of antibiotic-resistant gonorrhea stains circulating among the population.

DNA Microarray Characterization of Pathogens Associated with Sexually Transmitted Diseases

This study established a multiplex PCR-based microarray to detect simultaneously a diverse panel of 17 sexually transmitted diseases (STDs)-associated pathogens including Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma, Herpes simplex virus (HSV) types 1 and 2, and Human papillomavirus (HPV) types 6, 11, 16, 18, 31, 33, 35, 39, 54 and 58. The target genes are 16S rRNA gene for N. gonorrhoeae, M. genitalium, M. hominism, and Ureaplasma, the major outer membrane protein gene (ompA) for C. trachomatis, the glycoprotein B gene (gB) for HSV; and the L1 gene for HPV. A total of 34 probes were selected for the microarray including 31 specific probes, one as positive control, one as negative control, and one as positional control probe for printing reference. The microarray is specific as the commensal and pathogenic microbes (and closely related organisms) in the genitourinary tract did not cross-react with the microarray probes. The microarray is 10 times more sensitive than that of the multiplex PCR. Among the 158 suspected HPV specimens examined, the microarray showed that 49 samples contained HPV, 21 samples contained Ureaplasma, 15 contained M. hominis, four contained C. trachomatis, and one contained N. gonorrhoeae. This work reports the development of the first high through-put detection system that identifies common pathogens associated with STDs from clinical samples, and paves the way for establishing a time-saving, accurate and high-throughput diagnostic tool for STDs.

Recommendations for the laboratory-based detection of Chlamydia trachomatis and Neisseria gonorrhoeae--2014

This report updates CDC's 2002 recommendations regarding screening tests to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections (CDC. Screening tests to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections-2002. MMWR 2002;51[No. RR-15]) and provides new recommendations regarding optimal specimen types, the use of tests to detect rectal and oropharyngeal C. trachomatis and N. gonorrhoeae infections, and circumstances when supplemental testing is indicated. The recommendations in this report are intended for use by clinical laboratory directors, laboratory staff, clinicians, and disease control personnel who must choose among the multiple available tests, establish standard operating procedures for collecting and processing specimens, interpret test results for laboratory reporting, and counsel and treat patients. The performance of nucleic acid amplification tests (NAATs) with respect to overall sensitivity, specificity, and ease of specimen transport is better than that of any of the other tests available for the diagnosis of chlamydial and gonococcal infections. Laboratories should use NAATs to detect chlamydia and gonorrhea except in cases of child sexual assault involving boys and rectal and oropharyngeal infections in prepubescent girls and when evaluating a potential gonorrhea treatment failure, in which case culture and susceptibility testing might be required. NAATs that have been cleared by the Food and Drug Administration (FDA) for the detection of C. trachomatis and N. gonorrhoeae infections are recommended as screening or diagnostic tests because they have been evaluated in patients with and without symptoms. Maintaining the capability to culture for both N. gonorrhoeae and C. trachomatis in laboratories throughout the country is important because data are insufficient to recommend nonculture tests in cases of sexual assault in prepubescent boys and extragenital anatomic site exposure in prepubescent girls. N. gonorrhoeae culture is required to evaluate suspected cases of gonorrhea treatment failure and to monitor developing resistance to current treatment regimens. Chlamydia culture also should be maintained in some laboratories to monitor future changes in antibiotic susceptibility and to support surveillance and research activities such as detection of lymphogranuloma venereum or rare infections caused by variant or mutated C. trachomatis.