First evidence of widespread positivity to anticoagulant rodenticides in grey wolves (Canis lupus).

Second-generation Anticoagulant Rodenticides (ARs) can be critical for carnivores, due to their widespread use and impacts. However, although many studies explored the impacts of ARs on small and mesocarnivores, none assessed the extent to which they could contaminate large carnivores in anthropized landscapes. We filled this gap by exploring spatiotemporal trends in grey wolf (Canis lupus) exposure to ARs in central and northern Italy, by subjecting a large sample of dead wolves (n = 186) to the LC-MS/MS method. Most wolves (n = 115/186, 61.8 %) tested positive for ARs (1 compound, n = 36; 2 compounds, n = 47; 3 compounds, n = 16; 4 or more compounds, n = 16). Bromadiolone, brodifacoum and difenacoum, were the most common compounds, with brodifacoum and bromadiolone being the ARs that co-occurred the most (n = 61). Both the probability of testing positive for multiple ARs and the concentration of brodifacoum, and bromadiolone in the liver, systematically increased in wolves that were found at more anthropized sites. Moreover, wolves became more likely to test positive for ARs through time, particularly after 2020. Our results underline that rodent control, based on ARs, increases the risks of unintentional poisoning of non-target wildlife. However, this risk does not only involve small and mesocarnivores, but also large carnivores at the top of the food chain, such as wolves. Therefore, rodent control is adding one further conservation threat to endangered large carnivores in anthropized landscapes of Europe, whose severity could increase over time and be far higher than previously thought. Large-scale monitoring schemes for ARs in European large carnivores should be devised as soon as possible.

Comparative secretome analysis of Staphylococcus aureus strains with different within-herd intramammary infection prevalence.

Staphylococcus aureus is a major pathogen causing intramammary infection and mastitis in dairy cows. S. aureus genotypes (GT) can differ significantly in their ability to diffuse and persist in the herd; while the association of virulence gene carriage with epidemiological behavior remains unclear, a role for secreted proteins has been postulated. We characterized the secretome of six S. aureus strains belonging to two genotypes with opposite within-herd prevalence, GTB (high) and GTS (low), corresponding to sequence types (ST) 8 and 398, by high-resolution tandem mass spectrometry and differential analysis with Proteome Discoverer. Data are available via ProteomeXchange with identifier PXD029571. Out of 720 identified proteins, 98 were unique or more abundant in GTB/ST8 and 68 in GTS/ST398. GTB/ST8 released more immunoglobulin-binding proteins, complement and antimicrobial peptide inhibitors, enterotoxins, and metabolic enzymes, while GTS/ST398 released more leukocidins, hemolysins, lipases, and peptidases. Furthermore, GTB/ST8 released the von Willebrand factor protein, staphylokinase, and clumping factor B, while GTS released the staphylococcal coagulase and clumping factor A. Hence, GTB/ST8 secretomes indicated a higher propensity for immune evasion and chronicity and GTS/ST398 secretomes for cellular damage and inflammation, consistent with their epidemiological characteristics. Accordingly, GTS/ST398 secretions were significantly more cytotoxic against bovine PBMCs in vitro. Our findings confirm the crucial role of extracellular virulence factors in S. aureus pathogenesis and highlight the need to investigate their differential release adding to gene carriage for a better understanding of the relationship of S. aureus genotypes with epidemiological behavior and, possibly, disease severity.

Effect of Weeping Teats on Intramammary Infection and Somatic Cell Score in Dairy Goats.

Mastitis is the most common disease affecting dairy goats and causing economic losses. Although it is accepted that increased somatic cell count (SCC) is mainly a response to infection, its reliability for subclinical mastitis detection in goats is controversial. Indeed, many physiological and extrinsic variables can increase SCC, including breed, parity, age, stage of lactation, seasonal variations, and milking methods. In some animals, milk-secreting tissue is present in the wall of the teat and, in some instances, milk can filter through pores in the skin to the udder surface. This condition is known as "weeping teat" (WT). In these animals, mammary tissue might be prone to develop bacterial infections, although limited information is provided. Weeping teat seems to have a genetic background and is reported to be especially found in goat breeds selected for high milk production. Moreover, it is observed a genetic correlation between WT and decreased milk yield as well as increased somatic cell scores (SCS). Since information on this topic is very limited, this study aimed at investigating any possible relationship between WT, high SCC, and the presence of bacteria in goat milk. Alpine goat farms in Northern Italy were selected based on the presence of WT. Each herd was divided into two age-matched groups, identified as case (WT+) and control (WT-). Half-udder milk samples were collected aseptically at three timepoints; bacteriological analysis was performed, and SCC were determined and transformed in SCS. There was a positive association between SCS and the presence of bacteria in milk (P = 0.037) overall, whereas WT udder defect was associated with positive bacterial culture in just one herd (P = 0.053). Thus, this herd was further investigated, repeating the sampling and the analysis on the following year. The positive association between high SCS and the presence of bacteria in milk was then confirmed (P = 0.007), whereas no association with WT condition was found. These results indicate that WT defect is usually unrelated to both the outcome of milk bacterial culture and SCS. As a side outcome, we could confirm the role of bacterial infection in increasing SCS.

Tracking over time the developing gut microbiota in newborns admitted to a neonatal intensive care unit during an outbreak caused by ESBL-producing Klebsiella pneumoniae.

The establishment of gut microbiota is reportedly aberrant in newborns admitted to neonatal intensive care units (NICUs), with detrimental long-term health impacts. Here, we vertically tracked the developing gut bacterial communities of newborns hosted in an NICU during an outbreak sustained by ESBL Klebsiella pneumoniae and compared colonized and non-colonized patients. Most communities were highly variable from one sampling point to the next, and dominated by few taxa, often Proteobacteria and Enterobacteriaceae, with marked interindividual variability. This picture was retrieved independently of colonization status or clinical covariates. Our data support the emerging idea of preterm infants as a population in which no defined microbial signatures are clearly associated to clinical status. Instead, the strong pressure of the nosocomial environment, antibiotics and, in this case, the ongoing outbreak, possibly drive the evolution of microbiota patterns according to individual conditions, also in non-colonized patients.

Staphylococcus aureus From Goats Are Genetically Heterogeneous and Distinct to Bovine Ones.

Staphylococcus aureus is one of the major pathogens responsible for intramammary infections in small ruminants, causing severe economic losses in dairy farms. In addition, S. aureus can contaminate milk and dairy products and produce staphylococcal enterotoxins, being responsible for staphylococcal food poisoning. Currently, data on the population structure and the virulence gene patterns of S. aureus strains isolated from goat milk is limited. Therefore, this study aimed at defining Ribosomal Spacer PCR (RS-PCR) genotypes, clonal complexes (CC), spa types, and virulence gene profiles of S. aureus isolated from goat milk samples from Lombardy region of Italy. A total of 295 S. aureus isolates from 65 goat bulk tank milk samples were genotyped by RS-PCR. spa typing and virulence gene patterns of a subgroup of 88 isolates were determined, and MLST was performed on a further subgroup of 39 isolates, representing all the spa types identified during the analysis. This study revealed 7 major genotypic clusters (CLR, CLAA, CLZ, CLAW, CLBW, CLS, and CLI), of which S. aureus CLR (19.8%) was the most common. A total of 26 different spa types were detected, the most prevalent types were t1773 (24%), t5428 (22.7%), and t2678 (12.5%). Overall, 44.3% of all isolates harbored at least one enterotoxin gene. The most prevalent was the combination of sec-sel genes (35.2%). Based on their MLST, isolates were assigned to 14 different CC, with majority grouped as CC133 (24%), CC130 (19.6%), and CC522 (19.6%). The caprine S. aureus population was depicted with a minimum spanning tree and an evolutionary analysis based on spa typing and MLST, respectively. Then, the variability of such strains was compared to that of bovine strains isolated in the same space-time span. Our results confirmed that S. aureus isolates from goats have wide genetic variability and differ from the bovine strains, supporting the idea that S. aureus from small ruminants may constitute a distinct population.

Microbiota in Clostridioides difficile-Associated Diarrhea: Comparison in Recurrent and Non-Recurrent Infections.

Clostridioides difficile infection (CDI) is the leading cause of antibiotic-associated diarrhea, especially in hospitalized elderly patients, representing a global public health concern. Clinical presentations vary from mild diarrhea to severe pseudomembranous colitis that may progress to toxic megacolon or intestinal perforation. Antibiotic therapy is recognized as a risk factor and exacerbates dysbiosis of the intestinal microbiota, whose role in CDI is increasingly acknowledged. A clinically challenging complication is the development of recurrent disease (rCDI). In this study, using amplicon metagenomics, we compared the fecal microbiota of CDI and rCDI patients (sampled at initial and recurrent episode) and of non-infected controls. We also investigated whether CDI severity relates to specific microbiota compositions. rCDI patients showed a significantly decreased bacterial diversity as compared to controls (p < 0.01). The taxonomic composition presented significant shifts: both CDI and rCDI patients displayed significantly increased frequencies of Firmicutes, Peptostreptococcaceae, Clostridium XI, Clostridium XVIII, and Enterococcaceae. Porphyromonadaceae and, within it, Parabacteroides displayed opposite behaviors in CDI and rCDI, appearing discriminant between the two. Finally, the second episode of rCDI was characterized by significant shifts of unclassified Clostridiales, Escherichia/Shigella and Veillonella. No peculiar taxa composition correlated with the severity of infection, likely reflecting the role of host-related factors in determining severity.

The Possible Role of Gut Microbiota and Microbial Translocation Profiling During Chemo-Free Treatment of Lymphoid Malignancies.

The crosstalk between gut microbiota (GM) and the immune system is intense and complex. When dysbiosis occurs, the resulting pro-inflammatory environment can lead to bacterial translocation, systemic immune activation, tissue damage, and cancerogenesis. GM composition seems to impact both the therapeutic activity and the side effects of anticancer treatment; in particular, robust evidence has shown that the GM modulates the response to immunotherapy in patients affected by metastatic melanoma. Despite accumulating knowledge supporting the role of GM composition in lymphomagenesis, unexplored areas still remain. No studies have been designed to investigate GM alteration in patients diagnosed with lymphoproliferative disorders and treated with chemo-free therapies, and the potential association between GM, therapy outcome, and immune-related adverse events has never been analyzed. Additional studies should be considered to create opportunities for a more tailored approach in this set of patients. In this review, we describe the possible role of the GM during chemo-free treatment of lymphoid malignancies.