It’s teeming everywhere – and special microbes live on many everyday objects. How is that in the case of glasses? According to the results of a study, there are numerous harmless types of bacteria, but also potentially problematic ones that can affect the eye, for example. Regular wet cleaning therefore makes sense, say the scientists.
Germany – glasses country: almost half of the population wears glasses constantly or at least occasionally. Due to their position in the middle of the face, the proximity to the mouth and nose and the frequent skin contact, it seems clear that glasses are hardly germ-free. Researchers at Furtwangen University have investigated which microbes can be found there. To do this, they use a modern detection technology: They tracked down the microbes based on their genetic signatures. “Since many bacteria have not yet been able to be cultivated, we used molecular biological methods to gain insight into the colonization of the glasses,” says study director Markus Egert. For their analyzes, the researchers took samples of 30 glasses at three locations: glasses, ear hooks and nose pads.
In total, the scientists identified 5232 different types of bacteria from 665 genera. The highest biodiversity was found in the glasses and the lowest in the nose pads, the scientists report. Accordingly, many typical germs from the environment, such as pseudomonads, can also be found on the glasses. They evidently swirl over the air onto the flat parts of the glasses. In general, however, skin and mucous membrane bacteria such as cutibacteria, corynebacteria or staphylococci dominated the glasses. They apparently reach the structures through the skin of the face, hands or mouth and nose – or by breathing while breathing and cleaning glasses, explain Egert and his colleagues.
Potential bad guys too
As the detailed evaluations showed, the majority of the 13 most frequently identified species are potential pathogens. They can cause eye infections, especially in sensitive people. The study thus provides a comprehensive basis for a better assessment of glasses as germ carriers, say the scientists. They may play an important role as reservoirs of germs in recurring eye infections and the transmission of antibiotic-resistant bacteria.
But something can be done about this: Egert and his colleagues have already made it clear that the bacterial load on glasses can be reduced by around 95 percent by cleaning them with a damp cloth – for example with glasses cleaning cloths. “According to the current state of knowledge, damp cleaning with alcoholic or surfactant-containing glasses cleaning wipes or simply with water and washing-up liquid is also a sensible strategy for removing corona and other viruses from glasses after you have had contact with people who are coughing,” says Egert in conclusion.
Source: Furtwangen University, specialist article: Scientific Reports, doi: 10.1038 / s41598-020-62186-6