A new study finds drug-resistant pathogens can be spread via washing machines. This finding has been proven by hygienists at the University of Bonn for a children’s hospital where a Klebsiella oxytoca type was repeatedly transmitted to the newborns. Fortunately, no dangerous infection occurred to the newborns. The source of this infection was a conventional washing machine used to launder the clothes of the newborns. This case has now drawn attention, especially when antibiotic-resistant bacteria could also be transmitted via the washing machines in households with people who need nursing care. A further study of this will examine the distribution channel in more detail. The results of this new study are now published in the journal “Applied and Environmental Microbiology”.
Klebsiella oxytoca bacterium was increasingly detected during the routine hygiene screenings in the neonatal wards of a children’s hospital in Germany. The Klebsiella oxytoca bacterium can lead to gastrointestinal as well as respiratory infections and in the worst case, it can also result in fatal sepsis. In this particular case, common medications could only be used against Klebsiella oxytoca pathogen to a limited extent or not at all. Once after newborns were repeatedly colonized with the bacteria and intensive hygiene intervention measures were unsuccessful, the children’s hospital called in the Institute for Hygiene and Public Health (IHPH) of the University Hospital Bonn. Dr. Daniel Exner who is a hygiene officer at the Clinic and Polyclinic for General, Visceral, Thoracic & Vascular Surgery at the University Hospital Bonn, said that luckily, these newborns did not suffer any dangerous infections.
In order to trace the source and also the possible distribution pathways, several environmental samples from patient and also from the staff areas and suspected risk locations were compared with the samples from the newborns. Dr. Ricarda Schmithausen who is the Head of the One Health Department at IHPH said that Klebsiella oxytoca type was so unique that it was in this form which is not yet included in the databases of the National Reference Center for gram-negative hospital pathogens. This was advantageous because it allowed the team to study the distribution pathways to be clearly traced. Neither the parents of the babies nor the nursing staffs had transmitted these bacteria.
The transmission to newborns was via beanies and socks
Prof. Dr. Dr. Martin Exner who is the Director of the Institute for Hygiene and Public Health at the University Hospital Bonn, said that the Klebsiella oxytoca bacteria type was clearly identified in the detergent drawer and also on the door seal of a washing machine, which was used to launder the hand-knitted socks as well as the beanies of the babies on the ward. The Klebsiella oxytoca bacteria were passed on to the newborn babies via the clothing.
After the washing machines were removed, no further colonization of the premature babies was detected. This clearly demonstrates that the team has found the Klebsiella source, Schmithausen concluded. This is a special case & hospitals normally uses special washing machine and laundry processes where washing is done at high temperatures and also with disinfectants, or designated laundries handle the washing externally. On the neonatal ward, the infection case that occurred some time ago involved a standard washing machine. They decided to investigate this case in order to draw attention to possible problems with antibiotic-resistant bacterias that are now advancing into the domestic environments, said Schmithausen.
Some studies have already shown that drug-resistant bacteria can take hold in washing machines. Prof. Exner said that the team has proven for the first time that washing machines can be a source to spread antibiotic-resistant bacteria to humans. This study results also has consequences for the domestic environment. For environmental reasons, the trend in conventional household machines is towards lower temperatures of well below 60°C (140°F). According to the researchers, this is in principle a very positive development because it saves energy and protects the climate.
However, if elderly people requiring nursing care with open wounds or bladder catheters or younger people with suppurating injuries or infections lived in the household, laundry should be washed at higher temperatures, such as 60°C (140°F), to avoid the transmission of dangerous pathogens. This is actually a growing challenge for hygienists, as the number of people receiving nursing care from family members is constantly increasing.