Is the use of supermarket trolleys microbiologically safe? Study of microbiological contamination

Prevalence, genetic diversity, antibiotic resistance and biofilm formation of Acinetobacter baumannii isolated from urban environments

AIM

Acinetobacter baumannii is a well-known nosocomial pathogen that has been isolated from different clinical sources. This pathogen also causes community-acquired infections, with mortality rates as high as 64%. The exact natural habitat of this bacterium is still unknown. In this study, we investigated the prevalence of A. baumannii in diverse soil and high-touch surface samples collected from a university campus, malls, parks, hypermarkets and produce markets, roundabout playground slides, and bank ATMs.

METHODS AND RESULTS

All obtained isolates were characterized for their antibiotic susceptibility, biofilm formation capacities, and were typed by multi-locus sequence analysis. A total of 63 A. baumannii isolates were recovered, along with 46 A. pittii and 8 A. nosocomialis isolates. Sequence typing revealed that 25 A. baumannii isolates are novel strains. Toilets and sink washing basins were the most contaminated surfaces, accounting for almost 50% of the recovered isolates. A number of A. baumannii (n=10), A. pittii (n=19) and A. nosocomialis (n=5) isolates were recovered from handles of shopping carts and baskets. The majority of isolates were strong biofilm formers and 4 exhibited a multi-drug resistant (MDR) phenotype.

CONCLUSIONS

Our study is the first to highlight community restrooms and shopping carts as potential reservoirs for pathogenic Acinetobacter species. Further studies are required to identify the reasons associated with the occurrence of A. baumannii inside restrooms. Proper disinfection of community environmental surfaces and spreading awareness about the importance of hand hygiene may prevent the dissemination of pathogenic bacteria within the community.

SIGNIFICANCE AND IMPACT OF STUDY

Serious gaps remain in our knowledge of how A. baumannii spreads to cause disease. This study will advance our understanding of how this pathogen spreads between healthcare and community environments. In addition, our findings will help healthcare decision makers implement better measures to control and limit further transmission of A. baumannii.

Antimicrobial coatings for environmental surfaces in hospitals: a potential new pillar for prevention strategies in hygiene

Recent reports provide evidence that contaminated healthcare environments represent major sources for the acquisition and transmission of pathogens. Antimicrobial coatings (AMC) may permanently and autonomously reduce the contamination of such environmental surfaces complementing standard hygiene procedures. This review provides an overview of the current status of AMC and the demands to enable a rational application of AMC in health care settings. Firstly, a suitable laboratory test norm is required that adequately quantifies the efficacy of AMC. In particular, the frequently used wet testing (e.g. ISO 22196) must be replaced by testing under realistic, dry surface conditions. Secondly, field studies should be mandatory to provide evidence for antimicrobial efficacy under real-life conditions. The antimicrobial efficacy should be correlated to the rate of nosocomial transmission at least. Thirdly, the respective AMC technology should not add additional bacterial resistance development induced by the biocidal agents and co- or cross-resistance with antibiotic substances. Lastly, the biocidal substances used in AMC should be safe for humans and the environment. These measures should help to achieve a broader acceptance for AMC in healthcare settings and beyond. Technologies like the photodynamic approach already fulfil most of these AMC requirements.

Risk factors of non-typhoidal Salmonella gastroenteritis in hospitalised young children: a case-control study

OBJECTIVE

To explore risk factors associated with non-typhoidal Salmonella gastroenteritis in young children in Hong Kong.

DESIGN

A case-control study.

SETTING

Paediatrics wards at three public hospitals in Hong Kong.

PARTICIPANTS

Cases were children aged above 30 days to below 5 years hospitalised for gastroenteritis at three public hospitals in Hong Kong with culture confirmed non-typhoidal Salmonella infection. Controls were age-matched (±2 months) children admitted for a reason other than gastroenteritis.

MAIN OUTCOMES MEASURES

A face-to-face interview by using standardised questionnaire on exposures 3 days prior to illness. Adjusted OR (aORs) and 95% CIs were calculated using multivariable logistic regression.

RESULTS

A total of 102 cases and 204 age-matched controls were included in the analysis. Multivariable logistic regression revealed that having food purchased from places other than a supermarket, that is, from wet market/restaurant/farm (aOR, 2.64; 95% CI, 1.03 to 6.77; p=0.044) was a significant risk factor for non-typhoidal Salmonella infection. Having a household member with gastroenteritis symptoms (aOR, 2.03; 95% CI, 0.94 to 4.39; p=0.072) was of borderline significance and playing at a children's indoor playroom was a protective factor (aOR, 0.28; 95% CI, 0.09 to 0.85; p=0.024).

CONCLUSIONS

Consumption of food purchased from places other than a supermarket was the identified determinant factor for non-typhoidal Salmonella gastroenteritis in Hong Kong. Parents/caregivers should be alerted to this risk when choosing foods for their young children. The protective effect of playing in an indoor playroom could be confounded by socioeconomic factors and further investigation is required to better understand its potential implication. There was some support for person-to-person transmission and good family hygiene needs to be emphasised.