Site-specific molecular analysis of the bacteriota on worn spectacles.

Regularly touched surfaces are usually contaminated with microorganisms and might be considered as fomites. The same applies for spectacles, but only little is known about their microbial colonization. Previous cultivation-based analyses from our group revealed a bacterial load strongly dominated by staphylococci. To better account for aerotolerant anaerobes, slow growing and yet-uncultivated bacteria, we performed an optimized 16S rRNA gene sequencing approach targeting the V1-V3 region. 30 spectacles were swab-sampled at three sites, each (nosepads, glasses and earclips). We detected 5232 OTUs affiliated with 19 bacterial phyla and 665 genera. Actinobacteria (64%), Proteobacteria (22%), Firmicutes (7%) and Bacteroidetes (5%) were relatively most abundant. At genus level, 13 genera accounted for 84% of the total sequences of all spectacles, having a prevalence of more than 1% relative abundance. Propionibacterium (57%), Corynebacterium (5%), Staphylococcus (4%), Pseudomonas, Sphingomonas and Lawsonella (3%, each) were the dominant genera. Interestingly, bacterial diversity on the glasses was significantly higher compared to nosepads and earclips. Our study represents the first cultivation-independent study of the bacteriota of worn spectacles. Dominated by bacteria of mostly human skin and epithelia origin and clearly including potential pathogens, spectacles may play a role as fomites, especially in clinical environments.

A view to a kill? - Ambient bacterial load of frames and lenses of spectacles and evaluation of different cleaning methods.

Surfaces with regular contact with the human body are typically contaminated with microorganisms and might be considered as fomites. Despite spectacles being widespread across populations, little is known about their microbial contamination. Therefore, we swab-sampled 11 worn spectacles within a university setting as well as 10 worn spectacles in a nursing home setting. The microbial load was determined by aerobic cultivation. All spectacles were found to be contaminated with bacteria, with nose pads and ear clips having the highest density, i.e. at sites with direct skin contact. Summed over all sites, the median microbial load of the university spectacles (1.4 ± 10.7 x 10(3) CFU cm-2) did not differ significantly from the spectacles tested in the nursing home (20.8 ± 39.9 x 10(3) CFU cm-2). 215 dominant bacterial morphotypes were analyzed by MALDI biotyping. 182 isolates could be assigned to 10 genera, with Staphylococcus being the most common. On genus-level, bacterial diversity was greater on nursing home spectacles (10 genera) compared to the university environment (2 genera). Four cleaning methods were investigated using lenses artificially contaminated with Escherichia coli, Micrococcus luteus, a 1:2 mixture of E. coli and M. luteus, and Staphylococcus epidermidis (the dominant isolate in our study), respectively. Best cleaning results (99% -100% median germ reduction) were obtained using impregnated wipes; dry cleaning was less effective (85% -90% median germ reduction). Finally, 10 additional worn university spectacles were cleaned with wipes impregnated with an alcohol-free cleaning solution before sampling. The average bacterial load was significantly lower (0.09 ± 0.49 x 10(3) CFU cm-2) compared to the uncleaned university spectacles previously investigated. Spectacles are significantly contaminated with bacteria of mostly human skin origin-including significant amounts of potentially pathogenic ones and may contribute to eye infections as well as fomites in clinical environments.

Nosocomial infections in the ICU: Pens and spectacles as fomites.

Nosocomial infections are a major cause of morbidity and mortality. Non-medical objects known as fomites may have a role in their genesis. We investigated the significance of writing pens and spectacles as fomites. The study was conducted at Aga Khan University Hospital, Karachi, from July 2013 to September 2013. Cultures were taken from pens and/or spectacles of resident nurses, doctors and nursing assistants in intensive care unit (ICU). Organisms important in ICU nosocomial infections were targeted. Seven rounds of sampling over 3 weeks led to 55 pen and 5 spectacle samples. Growth was seen in 3(5.5%) pen samples and 1(20%) spectacle sample. Two (3.6%) pen cultures grew acinetobacter, 1)1.8%) grew candida and acinetobacter, and i spectacle culture grew vancomycin-resistant enterococcus faecium (VRE). Two out of the 4 (50%) personnel managing all ICU beds had growth. During the study, one or more ICU patients had infection with the same organisms. Pens and spectacles may be responsible for the spread of organisms like acinetobacter and VRE. Personnel managing multiple beds are more likely to carry contaminated fomites.

Prevalence of antiseptic-resistance genes in staphylococci isolated from orthokeratology lens and spectacle wearers in Hong Kong.

PURPOSE: To compare isolation of staphylococci from periorbital tissues and accessories of orthokeratology (ortho-k) lens and spectacle wearers and investigate prevalence of antiseptic-resistance (QAC) genes. To determine minimum inhibitory concentrations (MIC) of antiseptics and antibiotic susceptibility of isolates. METHODS: Staphylococci were isolated from eyelids, eyelashes, and conjunctival sacs of 23 ortho-k lens wearers and 20 spectacle wearers. Samples were also collected from ortho-k lenses, lens cases, and spectacle frames. Isolations of Staphylococcus aureus were compared between ortho-k subjects and controls for all samples and for coagulase-negative staphylococci (CNS) from conjunctival sacs. QAC genes were amplified in 110 S. aureus and 59 CNS isolates and prevalence compared in isolates from ortho-k lens and spectacle wearers. Associations were assessed between presence of QAC genes and antibiotic and antiseptic susceptibility. RESULTS: Although isolation of S. aureus did not differ significantly in periorbital samples from ortho-k and control subjects, QAC genes were significantly more common in both S. aureus and CNS from ortho-k subjects (odds ratio 4.4 and 10.74, respectively). Overall, qacA/B was the predominant gene detected, being present in 26.5% CNS and 11% S. aureus. smr and qacH were present in 12% of CNS, but were less common in S. aureus. QAC gene-positive isolates had higher MICs to benzalkonium chloride and chlorhexidine digluconate. CONCLUSIONS: Our results suggest that long-term use of multipurpose solutions containing quaternary ammonium compounds may select for carriage of organisms harboring QAC genes. As these genes are associated with antibiotic resistance, their increased prevalence in isolates from contact lens wearers is a concern.

Microbiological safety of glasses dispensed at 3D movie theatres.

Recent popularity of three-dimensional movies raised some concern about microbiological safety of glasses dispensed into movie theatres. In this study, we analysed the level of microbiological contamination on them before and after use and between theatres adopting manual and automatic sanitation systems. The manual sanitation system was more effective in reducing the total mesophilic count levels compared with the automatic system (P < 0.05), but no differences were found for coagulase-positive staphylococci levels (P = 0.22). No differences were found for mould and yeast between before and after levels (P = 0.21) and between sanitation systems (P = 0.44). We conclude that more evidences are needed to support microbiological risk evaluation.

Infection risk from surgeons' eyeglasses.

PURPOSE: To assess bacterial contamination of 20 eyeglasses from surgeons. METHODS: 40 samples were taken from the nose pad (n=20) and earpiece (n=20) of 20 eyeglasses from orthopaedic surgeons using a sterile swab stick soaked in sterile distilled water. Swabs were incubated and inoculated onto 3 plates: Staphylococcus/Streptococcus agar plate, Mannitol salt plate, and Chromogenic agar plate. Organisms isolated were identified. RESULTS: Of 20 eyeglasses, 19 were contaminated with Staphylococcus epidermidis (3 of them additionally grew S haemolyticus or S xylosus) and the remaining one grew S aureus . CONCLUSION: Eyeglasses are a source of surgical infection. Contamination can be caused by direct contact of the eyeglasses to the wound and indirect contact by the surgeon's fingers, splashes from saline irrigation, and through air. Therefore, disinfection should be performed for eyeglasses of surgeons. The use of surgical visor masks or filtered exhaust helmets (space suits) are alternatives.