Development of a real-time PCR for the specific detection of Waddlia chondrophila in clinical samples

Waddlia chondrophila is considered as an emerging human pathogen likely involved in miscarriage and lower respiratory tract infections. Given the low sensitivity of cell culture to recover such an obligate intracellular bacteria, molecular-based diagnostic approaches are warranted. We thus developed a real-time PCR that amplifies Waddlia chondrophila DNA. Specific primers and probe were selected to target the 16S rRNA gene. The PCR specifically amplified W. chondrophila but did not amplify other related-bacteria such as Parachlamydia acanthamoebae, Simkania negevensis and Chlamydia pneumoniae. The PCR exhibited a good intra-run and inter-run reproducibility and a sensitivity of less than ten copies of the positive control. This real-time PCR was then applied to 32 nasopharyngeal aspirates taken from children with bronchiolitis not due to respiratory syncytial virus (RSV). Three samples revealed to be Waddlia positive, suggesting a possible role of this Chlamydia-related bacteria in this settin

Individualized Catheter Surveillance among Neonates: A Prospective, 8-Year, Single-Center Experience

Objective. To monitor trends in central line-associated bloodstream infections and clinical sepsis (CLABICS) among neonates and to determine risk factors for infection, especially dwell time. Design. Prospective, single-center cohort study conducted from 2001 through 2008. Setting. University-affiliated tertiary care center. Methods. Individualized surveillance of catheter use and CLABICS episodes was conducted. Data were obtained via regular on-site visits made 3 times a week. Trends over time were estimated by Poisson regression, and risk factor analysis was conducted using a Cox proportional hazards model and logistic regression. Results. In all, 1,124 neonates were exposed to 2,210 central lines for a total of 12,746 catheter-days and 11,467 catheter-days at risk. The median duration of catheter use was 8 (interquartile range, 5-11) days for peripherally inserted central catheters (PICCs) and 4 (interquartile range, 2-6) days for umbilical catheters; 102 CLABICS episodes were detected. The median time to infection was 7 days. Incidence densities were 8.5 CLABICS episodes per 1,000 catheter-days at risk and 8.0 CLABICS episodes per 1,000 catheter-days. The highest rates were identified among neonates weighing 750 g or lower (14.9 CLABICS episodes per 1,000 catheter days at risk) and for PICCs (13.2 CLABICS episodes per 1,000 catheter days at risk). Catheter dwell time was associated with CLABICS for all umbilical catheters (odds ratio [OR], 1.2 per day of use [95% confidence interval {CI}, 1.1-1.3] P< .001) and for PICCs for up to 7 days (OR, 1.2 [95% CI, 1.1-1.4]; P = .041), but not thereafter (OR, 1.0 [95% CI, 0.9-1.1]; P = .90). Conclusion. Catheter dwell time is a risk factor for CLABICS during the first 7 days, irrespective of catheter type. After 7 days, PICCs are less likely to become infecte

Acceptability of COVID-19 Vaccine Among Hospital Employees in the Department of Paediatrics, Gynaecology and Obstetrics in the University Hospitals of Geneva, Switzerland

BACKGROUND AND AIMS: COVID-19 vaccination has been in the spotlight for almost a year now, both within the scientific community and in the general population. The issue of healthcare workers' (HCWs) hesitancy is particularly salient, given that they are at the forefront of the fight against COVID-19. Not only could unvaccinated HCW spread the disease, but HCWs are also critical messengers in building confidence towards COVID-19 vaccines. The goal of this study was to examine the perception of COVID-19 risk and of its vaccine acceptance among employees (i.e., HCW plus administrative staff) in the Department of Paediatrics, Gynaecology and Obstetrics at the University Hospitals of Geneva, for the purpose of drawing lessons on the determinants of vaccination morale. METHODS: We conducted an anonymous online survey comparing vaccination attitudes among vaccinated and unvaccinated workers in June 2021. It included questions on perception of COVID-19 risks and COVID-19 vaccines. Vaccination was not mandatory in our institution but was strongly recommended. RESULTS: In June 2021, 66% of the 1,800 employees of our department had received two doses of COVID-19 vaccine by the time of the survey. Among the employees, 776 participated (43%) to the survey, and among them 684 (88%) had chosen to be vaccinated. Participants working for longer in a hospital, with a chronic disease and a household contact with chronic disease were more likely to be vaccinated. Doctors were twice as likely to be vaccinated than nurses. Among unvaccinated hospital employees, 48 (52%) responded that they would not change their mind. Further, 35 (38%) were not feeling in danger of contracting severe COVID-19, and 32 (35%) had fears about possible side effects of COVID-19 vaccines that they wanted to discuss with a specialist. CONCLUSION: Our study indicates that, while two-third of the employees had been vaccinated, quite many were still hesitant. The unvaccinated explained their choice by not feeling at risk of complicated COVID-19, and because of fear of possible side effects associated with the vaccine. Investments in COVID-19 vaccine education is a critical component for increasing vaccine acceptance among the unvaccinated

Prevalence and diversity of Chlamydiales and other amoeba-resisting bacteria in domestic drinking water systems.

A growing number of human infections incriminate environmental bacteria that have evolved virulent mechanisms to resist amoebae and use them as a replicative niche. These bacteria are designated amoeba-resisting bacteria (ARB). Despite the isolation of these ARB in various human clinical samples, the possible source of infection remains undetermined in most cases. However, it is known that the ARB Legionella pneumophila, for instance, causes a respiratory infection in susceptible hosts after inhalation of contaminated water aerosols from various sources. The Chlamydiales order contains many ARB, such as Parachlamydia acanthamoebae or Simkania negevensis, previously implicated in human respiratory infections with no identified contamination sources. We thus investigated whether domestic water systems are a potential source of transmission of these Chlamydiales to humans by using amoebal culture and molecular methods. Other important ARB such as mycobacteria and Legionella were also investigated, as were their possible amoebal hosts. This work reports for the first time a very high prevalence and diversity of Chlamydiales in drinking water, being detected in 35 (72.9%) of 48 investigated domestic water systems, with members of the Parachlamydiaceae family being dominantly detected. Furthermore, various Legionella and mycobacteria species were also recovered, some species of which are known to be causal agents of human infections

Development of a new chlamydiales-specific real-time PCR and its application to respiratory clinical samples.

Originally composed of the single family Chlamydiaceae, the Chlamydiales order has extended considerably over the last several decades. Chlamydia-related bacteria were added and classified into six different families and family-level lineages: the Criblamydiaceae, Parachlamydiaceae, Piscichlamydiaceae, Rhabdochlamydiaceae, Simkaniaceae, and Waddliaceae. While several members of the Chlamydiaceae family are known pathogens, recent studies showed diverse associations of Chlamydia-related bacteria with human and animal infections. Some of these latter bacteria might be of medical importance since, given their ability to replicate in free-living amoebae, they may also replicate efficiently in other phagocytic cells, including cells of the innate immune system. Thus, a new Chlamydiales-specific real-time PCR targeting the conserved 16S rRNA gene was developed. This new molecular tool can detect at least five DNA copies and show very high specificity without cross-amplification from other bacterial clade DNA. The new PCR was validated with 128 clinical samples positive or negative for Chlamydia trachomatis or C. pneumoniae. Of 65 positive samples, 61 (93.8%) were found to be positive with the new PCR. The four discordant samples, retested with the original test, were determined to be negative or below detection limits. Then, the new PCR was applied to 422 nasopharyngeal swabs taken from children with or without pneumonia; a total of 48 (11.4%) samples were determined to be positive, and 45 of these were successfully sequenced. The majority of the sequences corresponded to Chlamydia-related bacteria and especially to members of the Parachlamydiaceae family

Undressing of Waddlia chondrophila to enrich its outer membrane proteins to develop a new species-specific ELISA.

Waddlia chondrophila, an obligate intracellular bacterium of the Chlamydiales order, is considered as an agent of bovine abortion and a likely cause of miscarriage in humans. Its role in respiratory diseases was questioned after the detection of its DNA in clinical samples taken from patients suffering from pneumonia or bronchiolitis. To better define the role of Waddlia in both miscarriage and pneumonia, a tool allowing large-scale serological investigations of Waddlia seropositivity is needed. Therefore, enriched outer membrane proteins of W. chondrophila were used as antigens to develop a specific ELISA. After thorough analytical optimization, the ELISA was validated by comparison with micro-immunofluorescence and it showed a sensitivity above 85% with 100% specificity. The ELISA was subsequently applied to human sera to specify the role of W. chondrophila in pneumonia. Overall, 3.6% of children showed antibody reactivity against W. chondrophila but no significant difference was observed between children with and without pneumonia. Proteomic analyses were then performed using mass spectrometry, highlighting members of the outer membrane protein family as the dominant proteins. The major Waddlia putative immunogenic proteins were identified by immunoblot using positive and negative human sera. The new ELISA represents an efficient tool with high throughput applications. Although no association with pneumonia and Waddlia seropositivity was observed, this ELISA could be used to specify the role of W. chondrophila in miscarriage and in other diseases

Zoonotic Potential of Rotavirus From Swine and Bovine in South of Taiwan

Rotavirus was recognized as the virus that responsible for causing acute gastroenteritis, especially young livestock. Taiwan Center for Disease Control (CDC) confirms the majority cases of acute gastroenteritis in Taiwan on February 2015 were caused by rotavirus. In this study, we report the incidence and zoonotic impact of rotavirus strain from Taiwan. This study examined 90 (swine) and 60 (bovine) fecal samples collected from south of Taiwan in March 2015. Detection of rotavirus using VP6 gene by RT-PCR technique with amplicons 379 bp. Zoonotic potential analysis based on nucleotide sequence and phylogenetic analysis. RT-PCR utilizing the primers specific for VP6 gene detected rotavirus with positive reactions 3/30 (10%) in piglets and 1/20 (5%) in the calf. Based on the nucleotide sequences and phylogenetic analysis indicated that 1 of 3 wild strains from swine rotavirus had 85.0% - 91.1% and 1 wild strain from bovine had 78.7% - 85.9% identity relations with human strains. These findings indicated that the wild strains of swine and bovine rotavirus may broadly spread and contribute to zoonotic transmission

Dynamics of Bacterial Hand Contamination During Routine Neonatal Care

Abstract Objective: To evaluate the dynamics of bacterial contamination of healthcare workers' (HCWs) hands during neonatal care. Setting: The 20-bed neonatal unit of a large acute care teaching hospital in Geneva, Switzerland. Methods: Structured observation sessions were conducted. A sequence of care began when the HCW performed hand hygiene and ended when the activity changed or hand hygiene was performed again. Alcohol-based handrub was the standard procedure for hand hygiene. An imprint of the five fingertips of the dominant hand was obtained before and after hand hygiene and at the end of a sequence of care. Regression methods were used to model the final bacterial count according to the type and duration of care and the use of gloves. Results: One hundred forty-nine sequences of care were observed. Commensal skin flora comprised 72.4% of all culture-positive specimens (n = 360). Other microorganisms identified were Enterobacteriaceae (n = 55, 13.8%); Staphylococcus aureus (n = 10, 2.5%); and fungi (n = 7,1.8%). Skin contact, respiratory care, and diaper change were independently associated with an increased bacterial count; the use of gloves did not fully protect HCWs' hands from bacterial contamination. Conclusions: These data confirm that hands become progressively contaminated with commensal flora and potential pathogens during neonatal care, and identify activities at higher risk for hand contamination. They also reinforce the need for hand hygiene after a sequence of care, before starting a different task, and after glove remova

Congenital syphilis in Switzerland: a marker of inequality? A mini-review

Syphilis remains a global public health problem, with growing incidence in most regions of the world, particularly among women of childbearing age. This alarming trend has led to an increase in cases of congenital syphilis, resulting in devastating consequences. While the implementation of measures by the World Health Organization (WHO) and various governments has contributed to a decline in the global incidence of congenital syphilis, many countries are facing an escalating crisis, as incidence continues to rise. This mini-review aims to provide an overview of the current state of this disease in different parts of the world, focusing on the most affected populations and highlighting congenital syphilis as a marker of vulnerability. It also focuses on Switzerland, a country with a robust economy, to identify shortcomings in the healthcare system that contribute to the persistence of congenital syphilis, even though the infection is easily detectable and treatable. In conclusion, this mini-review highlights the persistent risk of congenital syphilis worldwide, regardless of country prevalence or economic status, and underscores the need for sustained efforts to reach underserved women, emphasizing the vital role of comprehensive training for healthcare professionals