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A diagnosis of bacterial cystitis commonly relies on a positive microbiological culture demonstrating the presence of a significant number of colony-forming units/ml urine, as urine within the upper urinary tract, bladder and proximal urethra generally is considered sterile. Recent studies from human and veterinary medicine indicate the presence of non-culturable bacteria in culture-negative urine samples. The aim of the present study was to determine the occurrence of bacterial DNA in culture-negative urine samples from cats with signs of feline lower urinary tract disease (FLUTD) and healthy control cats by 16S ribosomal DNA PCR and subsequent sequencing. The study sample included 38 culture-negative urine samples from cats with FLUTD and 43 culture-negative samples from control cats. Eight culture-positive urine samples from cats with FLUTD were included as external positive controls in addition to negative reaction controls. Of possible methodological limitations, degradation of DNA due to storage, the use of non-sedimented urine for DNA isolation and lack of internal positive reaction controls should be mentioned. The positive controls were recognised, but occurrence of bacterial DNA in culture-negative urine from cats with or without signs of lower urinary tract disease was not demonstrated. However, considering the possible methodological limitations, the presence of bacterial DNA in the urine of culture-negative FLUTD cats cannot be excluded based on the present results alone. Therefore, a prospective study reducing the possibility of degradation of DNA due to storage, in combination with modifications enhancing the chance of detecting even lower levels of bacterial DNA in culture-negative samples, seems warranted. [ABSTRACT FROM AUTHOR]

Studies of feline lower urinary tract disease (FLUTD) among Norwegian cats have shown higher prevalences of bacterial cystitis than most previously published reports. The aims of the present study were to identify bacterial isolates obtained from the urine of Norwegian cats with FLUTD and their susceptibility to antimicrobial agents. Eighty-two bacterial isolates from 72 urine cultures obtained from 71 different cats were included. Escherichia coli, Staphylococcus species, Enterococcus species and Streptococcus species were the most frequently detected. The percentages of isolates susceptible to the included antimicrobial agents were as follows: enrofloxacin – 92%; trimethoprim/sulfonamide – 91%; nitrofurantoin – 89%; tetracycline – 78%; ampicillin – 73%; amoxicillin/clavulanic acid – 72%; trimethoprim – 68%; amoxicillin – 58%; cephalexin – 51%; spiramycin – 39%; penicillin – 34%; fucidic acid – 34%; lincomycin – 27%. Although several tendencies towards increasing antimicrobial resistance were detected among the isolates included, the species of bacteria isolated and their patterns of antimicrobial resistance were, in general, in concurrence with the existing literature. Thus, the results do not fully explain the higher prevalence of bacterial cystitis found in Norwegian cats. Moreover, additional explanatory factors beside the inclusion of primary accession cases rather than referred cases were not found. [ABSTRACT FROM PUBLISHER]

Organic acids are being used in animal husbandry due to their positive effects on overall health and growth rate in animal husbandry. However, little is known about the long-term effects of organic acids on the normal microbiota. In this work, an Escherichia coli strain isolated from a healthy pig was passed weekly for 20 months in medium with and without formic acid (FA) to investigate the effects of long-term exposure to organic acids. Passages were made using buffered medium at pH 5.25 and 6.1 with and without FA. Colonies showing reduced O antigen lipopolysaccharide production and increased susceptibility to FA were isolated after 12 months exposure to FA at pH 5.25 and after 20 months exposure to FA at pH 6.1. Adaptation to acid and bacterial growth was strongly affected by FA at pH 5.25. Also, after 2 months of serial passages, we observed colonies exhibiting multicellular behaviour, with production of fimbriae and an extracellular matrix. We conclude that long-term exposure to FA of an E. coli isolate from the normal intestinal microbiota is associated with various changes in the bacterial cell surface involving reduced O antigen expression and increased extracellular matrix production together with increased susceptibility to FA. [ABSTRACT FROM AUTHOR]

Until 2010 the last verified incidence of European foulbrood caused by the bacteria Melissococcus plutonius'in Norway dates back to 1980 when it was found in one apiary. EFB is listed as a notifiable disease in Norway and suspicion of EFB should be reported to the Norwegian Food safety Authority. In July 2010 EFB was suspected in several apiaries and samples analyzed at the Norwegian school of veterinary science verified the presence of M. Plutonius in the samples. The goal of the strategy chosen to fight the disease has been to eradicate M. Plutonius in Norwegian apiaries. Testing positive for M. plutoniusin or more colonies/apiariesentails destruction of all colonies and destruction/disinfection of all beekeeping equipment. In 2010 about 3000 colonies belonging to 45 beekeepers were destroyed. Economical compensation paid to the beekeepers for the sanitation in 2010 was about 1000- 1.500 000 €. In 2011, by May 11, M. Plutonius has been found in the apiaries of 8 beekeepers. These 8 beekeepers have about 400 colonies and areal located with in the area of the out break in 2010. In 2010 colonies were inspected for clinical symptoms and a brood comb were sent for analyses using a standard PCR technique on larvae. In 2011 a more sensitive PCR on wax debris has been used which allows sampling on the levels of apiaries. Whether the strategy to minimize the distribution and prevalence of EFB is successful or not will be known within the next few years. It is not known whether M. Plutonius in Norway belong to the same clone, or if several genetically different strains are involved. A number of Norwegian M. Plutonius is lates will be sequenced and provide answer on this question. The virulence of the Norwegian M. Plutonius strain (s) will be evaluated and compared with other high and low virulent strains. [ABSTRACT FROM AUTHOR]

Salmon lice (Lepeophtheirus salmonis) constitute a major challenge during the production of farmed Atlantic salmon in Norway. Preventive measures are considered to have a higher impact on sustainable control than lice treatment. Therefore, the studies presented here aimed to document the preventive effects of probiotic Aliivibrio spp. on lice infestation in experimental challenges. A reduction in salmon lice attachment success (58–65%) was observed in two separate aquarium trials, where Atlantic salmon were exposed to different compositions of Aliivibrio species 91 and 155 days prior to lice challenge. In a third trial, no difference in attachment was observed in groups exposed to probiotics 58 days prior to lice challenge compared to controls. However, a relative reduction in lice counts was seen on movable stages later in the trial. High levels of probiotic bacteria had no impact on lice viability in an in vitro bioassay on the preadult life stage; thus, the mechanism behind the preventative effect remains unknown. In conclusion, probiotic Aliivibrio bacteria can likely be used as a preventive tool to reduce salmon louse infestations in the salmon industry. The mechanism is still unknown, and this novel approach to lice control warrants further investigation to understand its optimal use and potential. [ABSTRACT FROM AUTHOR]

Simple Summary: Milk is a natural and essential nutrient for new-born mammals. Dogs were one of the first domesticated species to coexist with humans, and yet scientists lack some crucial information related to the anatomy and morphology of the canine mammary gland, the organ after which all mammals are named. This study investigated mammary glands' inner structures using intraductal corrosion casting. We intended to provide visualisation of the glandular and ductal structures and their branching presented as a three-dimensional image. The aim was to expand current knowledge in the anatomy field by describing the in situ position (i.e., the undisturbed shape and natural position) of glandular tissue and its ductal branching pattern. No obvious teat cistern was present. Glandular branch intertwining of different gland lobes without intercommunication was observed. Ascendant teat canals could drain single or multiple gland lobes or could end blind. Although it had a small sample size, this study confirmed that the intraductal cannulation of healthy canine mammary glands is possible through functional and developed orifices. New knowledge in this field could contribute to the better management and understanding of neoplastic and non-neoplastic conditions that veterinary clinicians and surgeons often encounter. Detailed knowledge related to the morphology, anatomy, physiology, and pathology of the canine mammary gland is scarce. Mammary tissue undergoes massive changes instructed by hormones multiple times within the lifespan of every bitch, affecting its appearance. To address the ductal system's appearance and to present how different our findings regarding the canine mammary gland are in comparison with the available literature, we obtained cadaveric specimens after euthanasia and mastectomy. All bitches were euthanised due to poor prognosis for their recovery from maladies unrelated to mammae. Using intraductal cannulation ex vivo, milk- or fluid-yielding ducts were perfused using VasQtec (polyurethane resin), which revealed casts, i.e., imprints of ducts and glandular structures in situ. We observed primary, vertically positioned ducts that ascended throughout the teat and continued branching to secondary, tertiary, etc., horizontally positioned ducts, which drained mammary gland lobes under the skin located close to the abdominal wall. The ascendant teat canal could be split into two and could be connected to gland alveoli or end blind. Alveolar formations were located along ducts and ductules in bigger and/or smaller clusters. This study is the first to generate a 3D image of canine ducts and glandular tissue using an intraductal approach. [ABSTRACT FROM AUTHOR]

Simple Summary: Albeit being crucial for survival of offspring, milk in the canine species is relatively poorly investigated. Normal milk microbiota is a proven and important source of bacteria able to colonize the gut of newborns described in several species, including humans. Scientists now consistently find a range of bacterial species in milk from healthy individuals lacking any clinical signs of mastitis. To elucidate this matter, we analyzed milk of healthy dams who delivered healthy puppies naturally and investigated whether it contains bacteria using standard culture media for aerobic and anaerobic growth of microorganisms. Results from 210 samples collected twice with an interval of 7 days in the early postpartum period reported Staphylococcaceae and Enterococcaceae to be most represented. No significant difference in bacterial growth from milk sampled first or second time was noted. Every dam had bacteria in most mammary glands, and only 14% of total samples had no bacterial growth. The composition of bacteria from all milk samples did not differ significantly, indicating consistent occurrence of bacteria in normal, healthy milk, not mere contamination. Considering the global threat posed by antibiotic resistance, their application should be avoided in individuals without additional clinical signs of inflammation. Studies of microbiota in normal canine milk from healthy dams are sparse. As is the case with blood and urine, it was considered that milk contains no microbiota. Any discovery of bacteria in canine milk is, therefore, often noted to be a result of contamination during sampling or interpreted as mastitis and treated with antibiotics. Milk was collected twice within 19 days after natural parturition from 11 lactating dams, with no general or local clinical signs of mastitis or other disease. The skin and teats were prepared with an antimicrobial protocol prior to each milk sampling. In total, 210 milk samples were collected and assessed for a number of bacterial colonies grown on each plate. Bacterial growth was detected in 180 samples (86%). Staphylococcus pseudintermedius, Enterococcus spp., Clostridium spp., Coagulase-Negative Staphylococci (CoNS), Streptococcus spp., Streptococcus canis, Bacillus spp., Pasteurella spp., and Escherichia coli were identified from pure and/or mixed bacterial growth, listed in descending order of occurrence. Despite the small sample size, the consistent occurrence of bacteria in early postpartum dams indicates a genuine occurrence of bacteria in canine milk, rather than random contamination. The finding of bacteria in the milk of dams should not, therefore, be the sole argument for the diagnosis of mastitis. [ABSTRACT FROM AUTHOR]

Background: Aliivibrio salmonicida is the causative agent of cold-water vibriosis in salmonids (Oncorhynchus mykiss and Salmo salar L.) and gadidae (Gadus morhua L.). Virulence-associated factors that are essential for the full spectrum of A. salmonicida pathogenicity are largely unknown. Chitin-active lytic polysaccharide monooxygenases (LPMOs) have been indicated to play roles in both chitin degradation and virulence in a variety of pathogenic bacteria but are largely unexplored in this context. Results: In the present study we investigated the role of LPMOs in the pathogenicity of A. salmonicida LFI238 in Atlantic salmon (Salmo salar L.). In vivo challenge experiments using isogenic deletion mutants of the two LPMOs encoding genes AsLPMO10A and AsLPMO10B, showed that both LPMOs, and in particular AsLPMO10B, were important in the invasive phase of cold-water vibriosis. Crystallographic analysis of the AsLPMO10B AA10 LPMO domain (to 1.4 Å resolution) revealed high structural similarity to viral fusolin, an LPMO known to enhance the virulence of insecticidal agents. Finally, exposure to Atlantic salmon serum resulted in substantial proteome re-organization of the A. salmonicida LPMO deletion variants compared to the wild type strain, indicating the struggle of the bacterium to adapt to the host immune components in the absence of the LPMOs. Conclusion: The present study consolidates the role of LPMOs in virulence and demonstrates that such enzymes may have more than one function. [ABSTRACT FROM AUTHOR]

Rapeseed meal is a sustainable feed ingredient that can be used as an alternative to imported soybean meal in European pig production. The gut microbiota plays an important role on pig physiology and health but the impact on microbiota of using rapeseed in diets is still not well known. In this study, 84 purebred Norwegian Landrace pigs with average initial weight of 25 kg were divided into two groups and fed for approximately three months with either a control diet containing soybean meal (CON) or a high-fiber experimental diet where 20% rapeseed meal (RSF) was included as an alternative to soybean meal in CON. The composition and function of microbiome in gut digesta samples were analyzed by performing 16S rRNA gene sequencing and culturing of bacteria. The microbiota diversity and composition were similar between the dietary treatments; however, relative abundance of a variety of bacterial groups and imputed functions of microbiome in the ileum and large intestine were altered when the pigs were fed with a rapeseed-based diet. It was notable that the immune-inducing bacterial group Mucispirillum and anti-inflammatory stimulating bacteria Lachnospira were more abundant in the ileum and large intestine of the RSF group, respectively. Moreover, there was a higher abundance of major amino acid fermenters and amylolytic bacteria in the CON group and a high abundance of putative short chain fatty acid producers in RSF group. In comparison with the CON group, the gut microbiome of RSF group possessed an enhanced potential for carbohydrate and energy metabolism and a reduced potential for bacterial pathogenicity-related pathways. [ABSTRACT FROM AUTHOR]