Evaluation of microbial occurrence in reusable robotic instruments for minimally invasive surgery: A pilot study

In recent decades, minimally invasive surgery has become the favoured surgical technique, with increasing utilisation of robotic surgery to enhance patient outcomes. However, the design complexity of surgical robotic instruments can pose challenges in maintaining adequate cleaning, disinfection and sterilisation-particularly of the device's interior. In our hospital, robotic instruments are reused for a maximum of ten successive patients, following the manufacturer's guidelines. To the best of our knowledge, neither the manufacturer nor ISO standards have specified any methods to determine the sterility of robotic instruments after cleaning, disinfection and sterilisation procedures. In a small pilot study, we used a locally developed protocol to evaluate the sterility of 20 da Vinci SI robotic instruments, with the aim of determining whether the recommended cleaning, disinfection and sterilisation process is adequate to achieve safe usage in subsequent patients. None of the 20 instruments showed viable micro-organisms, therefore the robotic instruments were considered sterile, and suitable for re-use. We recommend our protocol to other hospitals, to be used as an essential control element in the assessment of their unique reprocessing technique for robotic instruments.

Men and Women Have an Equal Oropharyngeal and Anorectal Chlamydia trachomatis Bacterial Load: A Comparison of 3 Anatomic Sites

BACKGROUND

The Chlamydia trachomatis bacterial load could have impact on transmission and sequelae. This is the first study providing comparison of C. trachomatis load at 3 anatomic sites estimated by cycle quantification (Cq) values.

METHODS

Data from 7900 C. trachomatis-positive samples were included (2012-2018). Cq value was used as an inversely proportional measure for C. trachomatis load. Multivariable linear regression analyses assessed differences in mean Cq values.

RESULTS

Vaginal swabs had the lowest Cq values (31.0) followed by urine (32.5), anorectal swabs (34.0), and oropharyngeal swabs (36.8) (P < .001). Men and women had similar oropharyngeal (36.4 vs 37.3; P = .13) and anorectal (34.2 vs 33.9; P = .19) Cq values. Men (32.2) and women (30.7) aged <25 years had lower urogenital Cq values than men (32.8) and women (31.9) aged ≥25 years (P < .001). HIV-positive patients had higher urogenital Cq values than HIV-negative patients (33.8 vs 32.6; P < .03).

CONCLUSIONS

Men and women have a similar C. trachomatis load at extragenital locations arguing for similar transmission potential and clinical relevance. Older patients and HIV-coinfected patients had lower C. trachomatis load, suggesting exposure to previous C. trachomatis infections potentially leading to partial immunity reducing load.

Genital and anal Chlamydia trachomatis bacterial load in concurrently infected women: a cross-sectional study

OBJECTIVES

Most international STI guidelines recommend Chlamydia trachomatis anorectal testing in women after self-reported sexual exposure or symptoms in women. However, it has been shown that the prevalence of anorectal C. trachomatis is as high (7%-17 %) in women who do not report anorectal intercourse (AI) as in women who do. This study assessed the correlation between the genital and anorectal C. trachomatis load in concurrently infected women for increased microbiological insight.

METHODS

A convenience sample of 105 women with a concurrent (genital and anorectal) C. trachomatis infection was included from the STI clinic in South Limburg, the Netherlands. Women provided self-collected vaginal and anorectal swabs. The C. trachomatis load was quantified with qPCR and the human cell load was assessed to ensure sample adequacy. Genital and anorectal C. trachomatis loads were divided into tertiles for comparison. The χ² test and linear regression were used to compare genital and anorectal C. trachomatis loads and identify determinants associated with load.

RESULTS

The overall median C. trachomatis load was higher in genital (median 5.3 log₁₀ C. trachomatis/ml) than anorectal samples (median 3.4, p ≤ 0.001), but both loads were within the same range. The genital and anal load categories were not related within one woman (p = 0.99), both in women with and without AI. The anorectal C. trachomatis load was in the same or higher load category than the genital load in 56% of women without AI, and 79% of women with AI.

CONCLUSIONS

Although no cut-off for clinical relevance is known, an anorectal C. trachomatis load in the same or higher load category than the genital C. trachomatis load is likely to be clinically relevant. Other measurements should also be taken into account, such as leucocytes or bacterial viability to distinguish infection from contamination or exposure.

Standardisation is necessary in urogenital and extragenital Chlamydia trachomatis bacterial load determination by quantitative PCR: a review of literature and retrospective study

OBJECTIVES

Pathogen load has been linked to disease severity in patients infected with HIV, resulting in international standards to adequately and reproducibly quantify load. Chlamydia trachomatis (CT) load has been inconsistently linked to disease severity since extensive differences exist in quantification methods (14 methods in 28 articles). Differences include normalisation for human cell load due to CT's intracellular nature, despite the inability to distinguish inflammatory cells from epithelial cells with molecular techniques. We compared the human cell load in CT-positive men and women at the genital and anal site to a CT-negative control group to estimate the impact of inflammatory cells in these samples.

METHODS

188 women (tested at genital and anal site) and 519 men (207 tested at the anal site and 312 tested at the urogenital site) were included from our STI-clinic in the Netherlands. Specimens were self-collected vaginal swabs, anal swabs and urine samples. Quantitative-PCR targeting the HLA-gene quantified human cell load. Mann-Whitney-U-test was used for statistical analyses.

RESULTS

The genital cell load had a similar range and median (6.5 log10) between CT-negative and CT-positive women . The urogenital cell load was significantly higher than the anal cell load (median 3.6 log10). The anal cell load was significantly higher in men with- than without anal CT infection (median 4.5 versus 3.9 respectively). The anal cell load is significantly higher in CT-positive men than in women. Both Neisseria gonorrhoeae-co-infections and reported anal intercourse significantly increased the human cell load in anal samples.

CONCLUSION

Standardisation in CT load studies is necessary as current studies show 14 different quantification methods in 28 studies . In this study we demonstrate the inappropriateness of normalising the CT load for the human cell load using molecular techniques, as the presence of inflammatory cells cannot be excluded.

Review of Chlamydia trachomatis viability methods: assessing the clinical diagnostic impact of NAAT positive results

INTRODUCTION

Chlamydia trachomatis (chlamydia) is the most commonly diagnosed bacterial sexually transmitted infection (STI) worldwide. The advancement of molecular techniques has made chlamydia diagnostics infinitely easier. However, molecular techniques lack the information on chlamydia viability. Where in routine diagnostics the detection of chlamydia DNA or RNA might suffice, in other patient scenarios, information on the viability of chlamydia might be essential. Areas covered: In this review, the authors discuss the specific strengths and limitations of currently available methods to evaluate chlamydia viability: conventional cell culture, messenger RNA (mRNA) detection and viability-PCR (V-PCR). PubMed and Google Scholar were searched with the following terms: Chlamydia trachomatis, Treatment failure, Anal chlamydia, Microbial viability, Culture, Viability-PCR, Messenger RNA, and Molecular diagnostics Expert commentary: Several techniques are currently available to determine chlamydia viability and thus the clinical relevance of a positive test result in clinical samples. Depending on the underlying research question, all three discussed techniques have their merits when testing for viability. However, mRNA methods show the most promise in determining the presence of a true infection, in case the chlamydia reticulate body can be specifically detected. Further research is needed to understand how to best apply viability testing in current chlamydia diagnostics.

Anorectal Chlamydia trachomatis Load Is Similar in Men Who Have Sex with Men and Women Reporting Anal Sex

BACKGROUND

Anorectal Chlamydia trachomatis (chlamydia) is frequently diagnosed in men who have sex with men (MSM) and in women, but it is unknown whether these infections are comparable in clinical impact and transmission potential. Quantifying bacterial load and identifying determinants associated with high bacterial load could provide more insight.

METHODS

We selected a convenience sample of MSM who reported anal sex (n = 90) and women with concurrent urogenital/anorectal chlamydia who reported anal sex (n = 51) or did not report anal sex (n = 61) from the South Limburg Public Health Service's STI unit. Bacterial load (Chlamydia/ml) was quantified for all samples and log transformed for analyses. Samples with an unquantifiable human leukocyte antigen (n = 9) were excluded from analyses, as they were deemed inadequately sampled.

RESULTS

The mean log anorectal chlamydia load (3.50) was similar for MSM and women who reported having anal sex (3.80, P = 0.21). The anorectal chlamydia load was significantly higher in these groups than in women who did not report having anal sex (2.76, P = 0.001). Detectable load values ranged from 1.81-6.32 chlamydia/ml for MSM, 1.74-7.33 chlamydia/ml for women who reported having anal sex and 1.84-6.31 chlamydia/ml for women who did not report having anal sex. Symptoms and several other determinants were not associated with anorectal chlamydia load.

CONCLUSIONS

Women who did not report anal sex had lower anorectal loads, but they were within a similar range to the other two groups. Anorectal chlamydia load was comparable between MSM and women who reported anal sex, suggesting similar transmission potential.

Chlamydia trachomatis load in population-based screening and STI-clinics: implications for screening policy

Objectives

If the Chlamydia trachomatis (CT) bacterial load is higher in high-risk populations than in the general population, this negatively affects the efficacy of CT screening incentives. In the largest retrospective study to date, we investigated the CT load in specimens collected from 2 cohorts: (1) attendants of a sexually transmitted infection (STI)-clinic and (2) participants of the Dutch population-based screening (PBS).

Methods

CT load was determined using quantitative PCR in CT-positive male urine and female cervicovaginal swabs. CT loads were converted into tertiles. Using multinominal logistic regression, independent association of cohort, symptoms, risk behaviour and human cell count on load were assessed.

Results

CT loads were determined in 889 CT-positives from PBS (n = 529; 71.8% female) and STI-clinics (n = 360; 61.7% female). In men, STI-clinic-cohort, human cell count and urethral discharge were positively associated with CT load. In women, PBS-cohort and cell count were positively associated with CT load. Both cohorts had the same range in CT load.

Conclusions

The general population has a similar range of bacterial CT load as a high-risk population, but a different distribution for cohort and gender, highlighting the relevance of population-based CT-screening. When CT loads are similar, possibly the chances of transmission and sequelae are too.