Quantitation of Neisseria gonorrhoeae from Women with Gonorrhea

Lowe, Thomas L.; Kraus, Stephen J.

doi:10.1093/infdis/133.6.621

Cited by 39 publications

(18 citation statements)

References 21 publications

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“…However, semen samples from males infected with gonorrhea on average contain 7 ϫ 10 6 CFU per ejaculate (12), similar to the gonococcal inoculum used in these studies (6 ϫ 10 6 CFU/well). Cervical aspirates of females with gonorrhea have been reported to contain 10 4 to 10 6 CFU/ml (16,34). In our studies the average number of CFU of gonococci adherent to epithelial cells in the controls falls within this range (1 ϫ 10 6 CFU/well), again lending support to the relevance of our experimental conditions.…”

Section: Discussionsupporting

confidence: 81%

Inhibition of Neisseria gonorrhoeae Epithelial Cell Interactions by Vaginal Lactobacillus Species

Spurbeck¹,

Arvidson

2008

Infect Immun

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High levels of Lactobacillus, the dominant genus of the healthy human vaginal microbiota, have been epidemiologically linked to a reduced risk of infection following exposure to the sexually transmitted pathogen Neisseria gonorrhoeae. In this work, a cell culture model of gonococcal infection was adapted to examine the effects of lactobacilli on gonococcal interactions with endometrial epithelial cells in vitro. Precolonization of epithelial cells with Lactobacillus jensenii, Lactobacillus gasseri ATCC 33323, or L. gasseri ATCC 9857 reduced gonococcal adherence by nearly 50%. Lactobacilli also inhibited gonococcal invasion of epithelial cells by more than 60%, which was independent of the effect on adherence. Furthermore, lactobacilli were able to displace adherent gonococci from epithelial cells, suggesting that these organisms have potential as a postexposure prophylactic. Thus, vaginal lactobacilli have the ability to inhibit gonococci at two key steps of an infection, which might have a significant effect in determining whether the gonococcus will be able to successfully establish an infection following exposure in vivo.Neisseria gonorrhoeae (gonococcus), the causative agent of gonorrhea, is an obligate human pathogen that infects an estimated 62 million people per year worldwide (www.who.org). Gonorrhea is treatable with antibiotics; however, the disease is still prevalent due in part to the high frequency of asymptomatic and subclinical infections in women, providing a significant reservoir for transmission. Untreated gonococcal infections ascend the reproductive tract in up to 45% of infected women and can lead to disseminated infection, pelvic inflammatory disease, ectopic pregnancy, or sterility. Thus, gonococcal infections place a significant health burden on our society.In the initial phase of a gonococcal infection in a female host, N. gonorrhoeae adheres to receptors on epithelial cells of the genital tract. Type IV pili are the primary adhesins (28), although several additional surface structures can also mediate adherence, including lipooligosaccharide (8), porin (30), and opacity proteins (Opa and PII) (17, 31). The process of adherence is a crucial step in mounting a successful infection; if the pathogen cannot adhere, it can be swept away from the epithelial cell surface by the flow of vaginal fluid. While the flow of vaginal fluid (on average, 1.55 g/8h) is not as rapid as that of urine, if the pathogen is nonadherent, it will eventually be cleared or killed by the antimicrobial agents present in the vaginal mucus (11, 33).The indigenous microbiota plays an important role in protecting the host from colonization by incoming pathogens. Lactobacillus is the predominant genus in the vaginal (37) and endocervical microbial communities (33) and is present at concentrations of 10 7 to 10 8 CFU/ml of vaginal fluid in healthy postmenarchal/premenopausal women (22). Lactobacillus jensenii and Lactobacillus gasseri are two of the most common species present, as determined by culture-independent techniqu...

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Section: Discussionsupporting

confidence: 81%

Inhibition of Neisseria gonorrhoeae Epithelial Cell Interactions by Vaginal Lactobacillus Species

Spurbeck¹,

Arvidson

2008

Infect Immun

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“…The total number of gonococci in the cervicovaginal area of women with gonorrhea has been estimated to average 1.5 x 105 colony-forming units, with a range from 4.0 x 102 to 1.8 x 107 colony-forming units (12). In our experiments, progesterone inhibited O2 uptake >50% at a concentration of 40 ,ug per 5 X 107 cells.…”

Section: Discussionmentioning

confidence: 46%

Effects of steroid hormones on Neisseria gonorrhoeae

Lysko¹,

Morse²

1980

Antimicrob Agents Chemother

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Various steroids were tested for their effects upon gonococcal O2 consumption and glucose catabolism. The ability to inhibit gonococcal O2 uptake appeared to be related to the molecular configuration of the steroid. The presence of lipophilic groups enhanced inhibition, whereas the addition of hydrophilic groups markedly diminished inhibition. Steroid inhibition decreased with an increasing number of polar groups. Glucose catabolism was inhibited by steroid hormones, and the degree of inhibition was influenced by pH and medium composition. Changes in growth medium and pH also resulted in differential steroid inhibition of O2 uptake. Under certain conditions, lactate partially relieved this inhibition. Gonococci that were grown in one environment and shifted to a new environment were inhibited by steroids to the same extent as if they had been originally grown in the new environment. The differential effects of medium and pH upon steroid inhibition may be due to structural rearrangements involving membrane phase transitions or to altered receptor affinity.

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“…Amplification inhibition can be the result of residual lysis and precipitation buffer components, device materials, or a reduction in reaction heating efficiency. However, the device detection limit was still well above expected patient sample bacterial loads (Priest et al 2017; Lowe and Kraus 1976). The frequency of device failure in our limit of detection study was 4%; only 2 out of 50 chips tested failed to amplify either NG or NGIC targets.…”

Section: Resultsmentioning

confidence: 85%

“…The lower detection limit of 500 genomic NG copies per reaction in our device is sensitive enough to detect infections in both urethral swabs (Priest et al 2017) and vaginal samples (Lowe and Kraus 1976). Of note, some apparent qPCR estimates of bacterial loads fell below our projected limit of detection (e.g., NG positive urethral samples #2, 3, 6, and 9 (Table S3)).…”

Section: Discussionmentioning

confidence: 99%

A paperfluidic platform to detect Neisseria gonorrhoeae in clinical samples

Horst

Rosenbohm

Kolluri

et al. 2018

Biomed Microdevices

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Globally, the microbe Neisseria gonorrhoeae (NG) causes 106 million newly documented sexually transmitted infections each year. Once appropriately diagnosed, NG infections can be readily treated with antibiotics, but high-risk patients often do not return to the clinic for treatment if results are not provided at the point of care. A rapid, sensitive molecular diagnostic would help increase NG treatment and reduce the prevalence of this sexually transmitted disease. Here, we report on the design and development of a rapid, highly sensitive, paperfluidic device for point-of-care diagnosis of NG. The device integrates patient swab sample lysis, nucleic acid extraction, thermophilic helicase-dependent amplification (tHDA), an internal amplification control (NGIC), and visual lateral flow detection within an 80 min run time. Limits of NG detection for the NG/NGIC multiplex tHDA assay were determined within the device, and clinical performance was validated retroactively against qPCR-quantified patient samples in a proof-of-concept study. This paperfluidic diagnostic has a clinically relevant limit of detection of 500 NG cells per device with analytical sensitivity down to 10 NG cells per device. In triplicate testing of 40 total urethral and vaginal swab samples, the device had 95% overall sensitivity and 100% specificity, approaching current laboratory-based molecular NG diagnostics. This diagnostic platform could increase access to accurate NG diagnoses to those most in need.

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Quantitation of Neisseria gonorrhoeae from Women with Gonorrhea

Cited by 39 publications

References 21 publications

Inhibition of Neisseria gonorrhoeae Epithelial Cell Interactions by Vaginal Lactobacillus Species

Inhibition of Neisseria gonorrhoeae Epithelial Cell Interactions by Vaginal Lactobacillus Species

Effects of steroid hormones on Neisseria gonorrhoeae

A paperfluidic platform to detect Neisseria gonorrhoeae in clinical samples

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