Improvement in Neisseria gonorrhoeae culture rates by bedside inoculation and incubation at a clinic for sexually transmitted infections

Abstract

Background Culture of Neisseria gonorrhoeae is essential for surveillance of complete antimicrobial susceptibility profiles. In 2014, the culture success rate of N. gonorrhoeae from samples taken at the clinic for sexually transmitted infections (STI clinic), Oslo University Hospital, Norway, was only 20%. The present study aimed to improve gonococcal culture rates using bedside inoculation of patient samples on gonococcal agar plates and incubation at the STI clinic. Methods This prospective quality improvement study was conducted by the STI clinic and the Department of Microbiology at Oslo University Hospital from May 2016 - October 2017. When culture of N. gonorrhoeae was clinically indicated, we introduced a parallel ‘bedside culture’ at the STI clinic and compared results with the standard culture at the microbiology department. Samples were taken from urethra, anorectum, pharynx and cervix. Culture rates were compared across symptomatic and asymptomatic anatomical sites. Results From 596 gonococcal-positive PCR samples, bedside culture had a significantly higher success rate of 57% compared to 41% with standard culture (p < 0.05). Overall, culture rate from symptomatic sites was 91% v. 45% from asymptomatic sites. The culture rates from different anatomical sites were as follows: urethra 93%, anorectum 64%, pharynx 28% and cervix 70%. Bedside culture significantly (p < 0.05) improved the culture rates for symptomatic urethral and asymptomatic pharyngeal samples. Conclusions Where feasible, bedside inoculation on gonococcal agar plates and incubation of samples from patients with gonorrhoea is recommended. This will improve the culture diagnostics and provide additional gonococcal isolates for antimicrobial resistance surveillance.

Chlamydial and Gonococcal Genital Infections: A Narrative Review

“…Thus, acting upon clinical suspicion, a different NAAT test, comprehending a different genomic target, should be used [56][57][58][59]. It is worth noting that it is still necessary and important to use the culture method in cases of resistance, specifically, to test the phenotype or genotype involved in antibiotic resistance mechanisms, also allowing the possible detection of new pathogen strains with mutations that cannot be detected in NAATs [66].…”

Gonorrhoeae must Compete with the Naturally Inhabitant of Microbial Community Right at the Outer Mucosal Surface to Authorize Infection

“…In laboratory culture milieu, N. gonorrhoeae actually need a complex nutrient related media requirements and with specific handling [55,80]. Specifically, for the growth medium, bacteria cannot grow in culture without a supplemented fountain of sufficient glutamine, glucose, iron, thiamine, phosphate and even carbon dioxide [55,81].…”