Transmission via the face is one route of methicillin-resistant Staphylococcus aureus cross-infection within a hospital

Nationality and body location alter human skin microbiome

Skin microbiomes function directly in human health and are affected by various external and internal factors. However, few studies have showed the variation of human skin microbiota at multiple body sites in individuals of different national origin living in the same environment. Here, using 16S rRNA sequencing, we investigated the diversity and function of skin microbiomes in different body locations of Chinese and Pakistani individuals from a single college in China. Body location and nationality significantly affected community structures, while season and gender only impacted community member. Due to different lifestyles and likely genetic characteristics of the hosts, Proteobacteria was more abundant in Pakistanis than in Chinese individuals. There were significant differences in the Shannon diversity of skin microorganisms among different skin sites of Chinese individuals, but not in Pakistanis. PICRUSt prediction indicated that gene functions involved in carbohydrate metabolism, lipid metabolism, and xenobiotics biodegradation and metabolism were higher in bacteria collected from Pakistanis than those from Chinese individuals, but the amino acid metabolism of skin microorganisms in Chinese people was higher. The relative abundances of potential pathogenic bacteria also differed in different body locations, providing a foundation for studying skin-associated bacterial diseases. Through a meta-analysis of 233 human skin samples from eight elevational sites in western China, we found that skin microbial diversity first decreased and then increased with increasing altitude. Network analysis showed positive correlation between altitude and Lactobacillus, Chryseobacterium, or Acinetobacter. Our results uncover the variation of human skin microbiota allowing future explorations of potential significance for human health. KEY POINTS: • Body location and nationality affect skin microbiota diversity and function. • Proteobacteria was more abundant in Pakistanis than in Chinese. • Skin microbial diversity first decreased and then increased with elevated altitude.

Hand-to-face contact behaviors during indoor activities in daily life among Korean adults: an observational pilot study using videotaping

OBJECTIVES

Hand-to-face contact (HFC) is the major route for the self-inoculation of pathogens. This study aimed to describe the characteristics of HFC behaviors among Korean adults during indoor activities.

METHODS

Thirty participants were enrolled in the study, and 2 hours of videotaped data were collected from each participant. Contact data were recorded by examining the frequency and duration of HFC on the videos. Three training sessions were conducted for 2 readers to ensure the accuracy and reliability of videotape reading. Re-reading and verification of selected video data were performed to confirm intrapersonal and interpersonal validity. Contact exposure (CE) was determined by multiplying the contact frequency (CF) by the contact duration (CD) to quantify the intensity of contact during the observation time (2 hours).

RESULTS

A total of 3,007 HFCs (1,305 mucous membrane contacts and 1,702 non-mucous membrane contacts) were observed for 60 person-hours. The median CF (person/2 hr) of the mucous membranes (eye; 4.0, nose; 15.5, mouth; 16.5) was 39.5/person and the median total CD was 177.0 sec/person. The median CE (frequency-duration/sec/person) was 5,795.0 (mouth: 1,356.0, nose: 600.0, eye: 57.5).

CONCLUSIONS

This study showed that the mouth and nose were the most frequent exposure sites for HFC. Avoiding habitual HFC, awareness of self-inoculation by HFC, and vigorous hand hygiene should be strengthened to prevent the spread of infections.

Antisuperbug Cotton Fabric with Excellent Laundering Durability

Multidrug-resistant superbugs are currently a severe threat to public health. Here, we report a novel kind of antisuperbug material prepared by irradiation induced graft polymerization of 1-butyl-3-vinyl imidazole chloride onto cotton fabric. The reduction of superbugs on this fabric is higher than 99.9%. Attributed to the strong covalent bonding between the graft chains and the cellulose macromolecules, the antisuperbug performance did not decrease even after 150 equiv of domestic laundering cycles. Covalent bonding also prevented the release of the antibacterial groups during application and guarantees the safety of the material, which was proved by animal skin irritation and acute oral toxicity tests.

Silver sulfadiazine–immobilized celluloses as biocompatible polymeric biocides

Sulfadiazine was immobilized onto cotton cellulose using ethylene glycol diglycidyl ether as a binder. Upon treatment with diluted silver nitrate aqueous solution, the sulfadiazine moieties in the immobilized celluloses were transformed into silver–sulfadiazine coordination complexes. The resulting silver sulfadiazine–immobilized celluloses provided a 6-log reduction of 108 CFU mL−1 of Staphylococcus aureus (Gram-positive bacteria), Escherichia coli (Gram-negative bacteria), methicillin-resistant Staphylococcus aureus (drug-resistant bacteria), vancomycin-resistant Enterococcus faecium (drug-resistant bacteria), and Candida albicans (fungi) in 30–60 minutes, and a 5-log reduction of 107 PFU mL−1 of MS2 virus in 120 minutes. The antibacterial, antifungal, and antiviral activities were both durable and rechargeable. Additionally, trypan blue assay suggested that the new silver sulfadiazine–immobilized celluloses sustained excellent mammal cell viability, pointing to great potentials of the new materials for a broad range of health care–related applications.