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Raw milk is considered a high-risk source of Campylobacter due to faecal contamination from healthy cattle and farm environments, thus linking raw milk consumption to global outbreaks. Detection of Campylobacter in raw milk poses challenges due to low contamination levels and antibacterial properties of the milk. Culture-based protocols for Campylobacter detection in milk vary, mainly with regard to pH adjustment and the choice of enrichment broth. This European collaborative study was organised by the EU Reference Laboratory (EURL) for Campylobacter together with eight EU National Reference Laboratories (NRL) for Campylobacter with the purpose to evaluate methods for culture-based detection of Campylobacter in raw cow's milk. The study was divided into two parts, an interlaboratory part and an intralaboratory part, both organised around the same two protocols. The aim of protocol 1 was to evaluate the impact of pH adjustment and storage of the milk on the culturability of Campylobacter over time. Aliquots of the spiked milk were adjusted either to pH 7.0 or pH 7.6 or left unadjusted. The milk was stored up to 48 h at refrigerated temperature and Campylobacter was quantified according to ISO 10272-2 on day 0, 1 and 2. The aim of protocol 2 was to evaluate which enrichment broth, Bolton broth (BB) or Preston broth (PB), showed highest sensitivity in detection of Campylobacter. The spiked milk was enriched in BB and PB as described in ISO 10272-1:2017 or ISO 10272-1:2017/Amd1.2023. In the interlaboratory part, each milk batch was collected locally by each participating NRL/EURL and inoculated with the same Campylobacter strain. In the follow-up intralaboratory part, the EURL-Campylobacter repeated the tests in protocol 1 and 2 but used different Campylobacter strains and strains subjected to thermal stress prior to inoculation. The results show that pH adjustment of raw milk has a negligible impact on culture-based detection of Campylobacter, regardless of strain and level of environmental stress. The composition of milk and properties of the inoculated strain influence culture-based detection of Campylobacter over storage time, and strains subjected to additional stress prior to inoculation in milk are reduced in culturability much faster than the same strains prepared under normal conditions. Finally, the study showed that PB without Campylobacter growth supplement is less effective than BB in detecting Campylobacter in raw milk., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The incidence of Chlamydia psittaci respiratory tract infections in humans has increased in Sweden in recent years. This study aimed to identify the transmission route by genotyping C. psittaci from infected humans and birds. 42 human C. psittaci samples and 5 samples from C. psittaci-infected birds were collected. Genotyping was performed using ompA sequencing, Multi-locus sequence typing, and/or SNP-based high-resolution melting-PCR. Epidemiological data was also collected, and a phylogenetic analysis was conducted. Analysis of ompA provided limited resolution, while the SNP-based PCR analysis successfully detected the Mat116 genotype in 3/5 passerine birds and in 26/29 human cases, indicating a high prevalence of this genotype in the human population. These cases were associated with contact with wild birds, mainly through bird feeding during winter or other outdoor exposure. Human cases caused by other genotypes (psittacine and pigeon) were less common and were linked to exposure to caged birds or pigeons. The SNP-genotype Mat116 is rare, but predominated in this study. The use of SNP-based PCR provided a better understanding of the C. psittaci transmission from birds to humans compared to ompA analysis. In Sweden, human psittacosis appears mainly to be transmitted from garden birds during bird feeding in the winter season., (Copyright © 2023 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

Coagulase-negative staphylococci and its subtype Staphylococcus epidermidis are major indigenous Gram-positive inhabitants of the human skin. Colonization occurs in direct connection with birth and terrestrial adaptation. This study focuses on factors that may influence skin colonization of the newborn infant that relates to the immune status of both the bacteria and the host. Skin is an effective barrier against bacteria, and this function is partly mediated by the presence of antimicrobial peptides including human cathelicidin peptide LL37. Gram-positive bacteria have been described to have adhesive pili on their surface that mediates specific attachment to the host. Here, we identify, by negative staining transmission electron microscopy (EM), two different types of pilus-like structures commonly expressed on S. epidermidis isolated from newborn infants. We also show that the cathelicidin antimicrobial peptide LL37, constitutively expressed in the skin barrier of the newborn, significantly inhibited growth of S. epidermidis indicating its importance for the ecological stability of the skin microbiota. Further studies are required to elucidate molecular mechanisms of host-microbe interactions, both for the maintenance of a mutually beneficial homeostatic relationship and for the protection of self when it results in overt disease.

The epidemiology and genetic variability of circulating respiratory syncytial virus (RSV) strains in Stockholm during the season 2002-2003 were studied in consecutive RSV isolates derived from respiratory samples and diagnosed in the laboratory. Two hundred thirty-four viruses were sequenced. The samples were mainly from children under 1 year old (79%). The phylogeny of the N-terminal part of the G gene was studied after amplification and sequencing. One hundred fifty-two viruses belonged to subgroup B and 82 to subgroup A. The subgroup A viruses could be further divided into genotypes GA2 (25) and GA5 (57) and the subgroup B viruses into GB3 (137) and SAB1 (15) strains. These strains clustered with subgroup A and subgroup B strains from Kenya from the same period, as well as with strains from Great Britain from 1995 to 1998. The dominance of subgroup B strains in Stockholm during 2002-2003 is in agreement with findings from other parts of the world during the same years. Only two genotypes of subgroup A, GA2 and GA5, were circulating during this time, and GA2 has been circulating in Sweden for more than 20 years. Consecutive strains from the same individual displayed no variability in the sequenced region, which was also true of strains that had been passaged in cell cultures., ((c) 2007 Wiley-Liss, Inc.)