ABSTRACT Staphylococcus chromogenes TA showed significantly lower growth under iron-deprived conditions, and adding an iron supplement (lactoferrin or ferritin) resulted in no improvement in growth; in contrast, growth of S. chromogenes IM was significantly recovered with ferritin iron supplementation. Only Staphylococcus hominis strains originating from quarter milk were able to significantly utilize ferritin as an iron source to reverse the growth inhibition caused by chelating agent 2,2ʹ-bipyridyl in varying degrees. Both S. chromogenes strains (IM and TA) and all S. hominis strains were unable to significantly use lactoferrin as an iron source for growth recovery.

Salmonellosis is still one of the most reported zoonoses worldwide and poultry meat is a major source, as chickens are often persistent carriers of Salmonella. Medium-chain fatty acids (MCFA) are known for their strong antimicrobial activity. MCFAs used today in the animal feed industry, however, mainly originate from the palm oil industry, which is notorious for its negative impact on the climate. We investigated the effect of a specific blend of palm-free MCFAs (ranging from C6 to C9) on Salmonella Enteritidis (SE) colonization in broiler chickens and in vitro SE characteristics. Fifty Ross 308 broiler chickens were randomly divided in 2 treatment groups. Chickens received either un-supplemented feed or feed supplemented with 300 ppm MCFAs from D0 onwards. On D7, all chickens were orally inoculated with 1600 CFU of SE. Cloacal swabs (D11) and samples of liver and caeca (D12) of all animals were collected and SE was enumerated. Percentage of SE-positive caecum samples was significantly (P = 0.044) reduced in birds receiving MCFAs compared to those receiving unsupplemented feed (36% vs. 64%). In vitro work performed with the same SE strain showed that preincubating the Salmonella bacteria with MCFAs at a sub-minimal inhibitory concentration significantly (p < 0.05) reduced bacterial adhesion to and invasion in Caco-2 cells, which may explain the observed reduction in intestinal SE colonization in the in vivo trial. Together, these results show that the tested eco-friendly MCFA blend could be a promising tool in the control of Salmonella in broilers.

Staphylococcus chromogenes TA showed significantly lower growth under iron-deprived conditions, and adding an iron supplement (lactoferrin or ferritin) resulted in no improvement in growth; in contrast, growth of S. chromogenes IM was significantly recovered with ferritin iron supplementation. Only Staphylococcus hominis strains originating from quarter milk were able to significantly utilize ferritin as an iron source to reverse the growth inhibition caused by chelating agent 2,2'-bipyridyl in varying degrees. Both S. chromogenes strains (IM and TA) and all S. hominis strains were unable to significantly use lactoferrin as an iron source for growth recovery.

Staphylococcus hominis, a member of the non-aureus staphylococci (NAS) group, is part of the human and animal microbiota. Although it has been isolated from multiple bovine-associated habitats, its relevance as a cause of bovine mastitis is currently not well described. To successfully colonize and proliferate in the bovine mammary gland, a bacterial species must be able to acquire iron from host iron-binding proteins. The aims of this study were (1) to assess the genetic diversity of S. hominis isolated from bovine quarter milk, rectal feces, and teat apices, and (2) to investigate the capacity of bovine S. hominis isolates belonging to these different habitats to utilize ferritin and lactoferrin as iron sources. To expand on an available collection of bovine S. hominis isolates (2 from quarter milk, 8 from rectal feces, and 19 from teat apices) from one commercial dairy herd, a subsequent single cross-sectional quarter milk sampling (n = 360) was performed on all lactating cows (n = 90) of the same herd. In total, 514 NAS isolates were recovered and identified by MALDI-TOF mass spectrometry; the 6 most prevalent NAS species were S. cohnii (33.9%), S. sciuri (16.7%), S. haemolyticus (16.3%), S. xylosus (9.6%), S. equorum (9.4%), and S. hominis (3.5%). A random amplified polymorphic DNA (RAPD) analysis was performed on 46 S. hominis isolates (19 from quarter milk, 8 from rectal feces, and 19 from teat apices). Eighteen distinct RAPD fingerprint groups were distinguished although we were unable to detect the presence of the same RAPD type in all 3 habitats. One S. hominis isolate of a distinct RAPD type unique to a specific habitat (8 from quarter milk, 3 from rectal feces, and 4 from teat apices) along with the quality control strain Staphylococcus aureus ATCC 25923 and 2 well-studied Staphylococcus chromogenes isolates ("IM" and "TA") were included in the phenotypical iron test. All isolates were grown in 4 types of media: iron-rich tryptic soy broth, iron-rich tryptic soy broth deferrated by 2,2'-bipyridyl, and deferrated tryptic soy broth supplemented with human recombinant lactoferrin or equine spleen-derived ferritin. The growth of the different strains was modified by the medium in which they were grown. Staphylococcus chromogenes TA showed significantly lower growth under iron-deprived conditions, and adding an iron supplement (lactoferrin or ferritin) resulted in no improvement in growth; in contrast, growth of S. chromogenes IM was significantly recovered with iron supplementation. Staphylococcus hominis strains from all 3 habitats were able to significantly utilize ferritin but not lactoferrin as an iron source to reverse the growth inhibition, in varying degrees, caused by the chelating agent 2,2'-bipyridyl.

Agricultural operations are important sources of organic dust containing particulate matter (PM) and endotoxins, which have possible negative health consequences for both humans and animals. Dust concentrations and composition in calf barns, as well as the potential health effects for these animals, are scarcely documented. The objective of this study was to measure PM fractions and endotoxin concentrations in calf barns and study their associations with lung consolidation, respiratory tract inflammation, and infection in group-housed calves. In this cross-sectional study, samples from 24 dairy farms and 23 beef farms were collected in Belgium from January to April 2017. PM1.0, PM2.5 and PM10 (defined as particulate matter passing through a size-selective inlet with a 50% efficiency cut-off at a 1.0-μm, 2.5-μm, and 10-μm aerodynamic diameter, respectively) were sampled during a 24-h period using a Grimm aerosol spectrometer (Grimm Aerosol Technik Ainring GmbH & Co. KG). Endotoxin concentration was measured in the PM10 fraction. Thoracic ultrasonography was performed and broncho-alveolar lavage fluid was collected for cytology and bacteriology. Average PM concentrations were 16.3 µg/m3 (standard deviation, SD: 17.1; range: 0.20-771), 25.0 µg/m3 (SD: 25.3; range: 0.50-144.9), and 70.3 µg/m3 (SD: 54.5; range: 1.6-251.2) for PM1.0, PM2.5, and PM10, respectively. Mean endotoxin in the PM10 fraction was 4.2 endotoxin units (EU)/µg (SD: 5.50; range: 0.03-30.3). Concentrations in air were 205.7 EU/m3 (SD: 197.5; range: 2.32-901.0). Lung consolidations with a depth of ≥1, ≥3, and ≥6 cm were present in 43.1% (146/339), 27.4% (93/339), and 15.3% (52/339) of the calves, respectively. Exposure to fine (PM1.0) PM fractions was associated with increased odds of lung consolidations of ≥1 cm (odds ratio, OR: 3.3; confidence interval (CI): 1.5-7.1), ≥3 cm (OR: 2.8; CI: 1.2-7.1), and ≥6 cm (OR: 12.3; CI: 1.2-125.0). The odds of having lung consolidations of ≥1 cm (OR: 13.9; CI: 3.4-58.8) and ≥3 cm (OR: 6.7; 1.7-27.0) were higher when endotoxin concentrations in the dust mass exceeded 8.5 EU/µg. Broncho-alveolar lavage fluid neutrophil percentage was positively associated with PM10 concentration, and epithelial cell percentage was negatively associated with this fraction. Concentration of PM2.5 was positively associated with epithelial cell percentage and isolation of Pasteurella multocida. Although concentrations of fine dust are lower in calf barns than in poultry and pig housings, in this study they were associated with pneumonia in calves. Dust control strategies for reducing fine dust fractions in calf barns may benefit human and animal respiratory health.

Major disease outbreaks caused by Streptococcus equi subsp. zooepidemicus seldom are reported in poultry. Besides acute septicemia, infection can result in a subacute or chronic form of disease with described mortality rates of 11% to 80%. Previously, the source of infection in poultry was linked to horses in which this bacterium can be present as an opportunistic pathogen on mucus membranes. The main route of spreading and being maintained within a poultry flock, after entering the stable, however, remains unclear. This case report describes an outbreak associated with S. zooepidemicus affecting a flock of 28 500 layer hens housed in an aviary system with free range. Besides sudden deaths, clinical signs of depression were noticed. Between 44 and 61 wk of age a total mortality of 23% was observed. Egg production dropped from 92% to 83%. Bacterial titration revealed substantial numbers of S. zooepidemicus present in the ceca of a healthy chicken. This novel finding hypothesizes that transmission of the infection within the flock might occur through the fecal route.

Subclinical Salmonella Typhimurium infections occur frequently in pigs and constitute a major risk for human salmonellosis. With the currently available control measures, Salmonella Typhimurium infections in pigs remain difficult to control. Vaccination has been proposed to be an effective tool to control infections at farm level. In the current study, the effect of group vaccination of sows and gilts against Salmonella Typhimurium is evaluated on Salmonella prevalence in fecal and overshoe samples and ileocecal lymph nodes, and on serology in the sows and their offspring in three subclinically infected pig farms. In each farm, all sows and gilts were vaccinated twice, three weeks apart, with an attenuated histidine-adenine auxotrophic vaccine (Salmoporc®, IDT Biologika). From three months after the group vaccination onwards, all sows were given a booster dose three weeks before every farrowing. The farms were monitored bacteriologically and serologically from 12 months before until 15 months after the group vaccination. After group vaccination, no significant effect was detected in the prevalence of Salmonella Typhimurium in the fecal and overshoe samples collected in the sows (before: 2 %, after: 0 %) and their offspring at 18 weeks (before: 17 %, after: 11 %) and at 26 weeks of age (before: 15 %, after: 7 %), and when combining the results of the offspring at 18 and 26 weeks of age (before: 16 %, after: 9 %). Also, no significant effect was detected in the prevalence of Salmonella Typhimurium positive lymph nodes of sows (before and after: 0 %) and their offspring (before: 4 %, after: 7 %). Regarding serology, the mean S/P-ratios of the sows were significantly higher after the group vaccination, compared to before group vaccination (before: 1.50, after: 2.32, p < 0.001). The mean S/P-ratios of the offspring at slaughter age were significantly lower after the group vaccination, compared to before group vaccination (before: 1.71, after: 1.04, p = 0.001). In conclusion, group vaccination of sows and gilts resulted in a more beneficial serological status of the offspring, but did not significantly decrease Salmonella Typhimurium excretion and lymph node contamination.

We conducted a longitudinal study to evaluate the effect of non-aureus staphylococci (NAS) causing subclinical intramammary infections (IMI) on quarter milk somatic cell count (qSCC) and quarter milk yield (qMY). In total, 324 quarters of 82 Holstein Friesian heifers were followed from calving to 130 d in milk (DIM) and were sampled 10 times each at 14-d intervals. The IMI status of each quarter was determined based on bacterial culture results at the current and previous or next sampling day, or both. The qSCC was determined on each sampling day and the average qMY on sampling day was available through stored daily milk weight data in the management program of the automatic milking system. A transient IMI (tIMI) was defined as a case where a specific pathogen was isolated from a quarter on only one sampling day and not on the previous or next sampling day. When the same bacterial strain, as defined by random amplification of polymorphic DNA-PCR, was isolated from the same quarter on multiple sampling days, it was defined as a persistent IMI (pIMI) status on those sampling days; a pIMI episode was defined as the combination of multiple consecutive pIMI statuses with the same bacterial strain on different sampling days. During this study, 142 subclinical IMI with NAS occurred in 116 different quarters from 64 animals, yielding in total 304 NAS isolates belonging to 17 different species. The prevalence of NAS was highest in the first 4 DIM. Overall, the predominant species was Staphylococcus chromogenes (52% of the isolates), followed by S. epidermidis (9.2%), S. xylosus (8.2%), and S. equorum (5.9%). Staphylococcus chromogenes was the only species for which an effect on qSCC and qMY could be analyzed separately; the other NAS species were considered as a group because of their low prevalence. Eighteen out of 40 IMI (45%) caused by S. chromogenes persisted over at least 2 sampling days, whereas only 10 of 102 (9.8%) IMI caused by other NAS species persisted for at least 2 sampling days. The average duration of pIMI episodes was 110.4 d for S. chromogenes and 70 d for the other NAS species. Remarkably, 17 of the 18 pIMI episodes with S. chromogenes started within the first 18 DIM. The qSCC was highest in quarters having a pIMI with a major pathogen, followed by quarters having a pIMI with S. chromogenes, and a pIMI with other NAS. Transient IMI with other NAS or with a major pathogen caused a small but significantly higher qSCC, whereas the qSCC in quarters having a tIMI with S. chromogenes was not statistically different compared with noninfected quarters. No significant differences in qMY were observed between quarters having a pIMI or tIMI with S. chromogenes or with the other NAS species compared with noninfected quarters, despite the higher qSCC. Quarters having a pIMI with major pathogens showed significantly lower daily milk production. Surprisingly, quarters that cured from an IMI with S. chromogenes had a significantly lower qMY than noninfected quarters.

In deze casus wordt botryomycose van de uterus beschreven als oorzaak van vruchtbaarheidsproblemen bij runderen. Op drie bedrijven met Belgisch witblauwe runderen werden meerdere koeien na keizersnede niet meer drachtig na herhaalde kunstmatige of natuurlijke inseminatie. Op rectaal onderzoek werden op sommige uteri knobbels van 1 cm diameter vastgesteld. Na opeenvolgende onderzoeken en staalnamen bleek uit anatomo-pathologisch en bacteriologisch onderzoek van twee uteri dat botryomycose door infectie met Pseudomonas aeruginosa na keizersnede de meest waarschijnlijke oorzaak van de onvruchtbaarheid was. Preventie bestond voornamelijk uit een verbeterde hygiëne bij chirurgische ingrepen.

Non-aureus staphylococci (NAS) are predominantly isolated from bovine milk samples of quarters suffering from subclinical mastitis. They are also abundantly present on dairy cows' teat apices and can be recovered from bovine fecal samples, as recently described. Differences in ecology, epidemiology, effect on udder health, and virulence or protective traits have been reported among the species within this group. The objectives of this study were (1) to describe the species-specific distribution of NAS in 3 bovine-associated habitats, namely quarter milk, teat apices, and rectal feces, and (2) to evaluate the virulence potential of NAS by comparing their distribution in contrasting milk sample strata and the presence of selected virulence genes. A cross-sectional, systematic sampling procedure was followed in 8 dairy herds that participated in the local Dairy Herd Improvement program in Flanders, Belgium. Quarter milk samples (n = 573) were collected from 144 lactating cows in 8 herds. In 5 of the 8 herds, teat apex swabs (n = 192) were taken from 15 lactating cows, before and after milking, and from 18 dry cows. In the same 5 herds, rectal feces were sampled from 80 lactating cows (n = 80), taking into account that a cow could only serve as the source of one type of sample. In addition, milk samples of all clinical mastitis cases were continuously collected during the 1-yr study period from March 2017 to March 2018 in the 8 herds. In total, 1,676 Staphylococcus isolates were phenotypically identified and subjected to MALDI-TOF mass spectrometry. Thirty-three, 98, and 28% of all quarter milk, teat apex, and rectal fecal samples were NAS-positive, respectively, reaffirming the presence of NAS in rectal feces. The overall predominant species in the 3 habitats combined were Staphylococcus haemolyticus, Staphylococcus chromogenes, and Staphylococcus hominis. Four, 16, and 12% of the healthy quarters (quarter milk somatic cell count ≤50,000 cells/mL of milk), quarters with subclinical mastitis (quarter milk somatic cell count >50,000 cells/mL of milk), and quarters with clinical mastitis, respectively, were NAS-positive, suggesting that the potential to cause (mild) clinical mastitis is present among NAS. This was substantiated by comparing the presence of virulence genes of NAS isolates originating from contrasting milk sample strata (healthy quarters and quarters with clinical mastitis).

In this case report, botryomycosis of the uterus is described as the cause of fertility problems in cattle after caesarian section. Several cows of three Belgian Blue cattle herds failed to become pregnant after repeated artificial or natural insemination. On the uterus of some of the these cows, nodes of 1 cm in diameter were found on rectal examination. Anatomopathological and bacteriological examination of two affected uteri together with on-farm investigations indicated botryomycosis caused by Pseudomonas aeruginosa after caesarian section as the most probable cause of the infertility. Prevention was primarily based on improving the hygienic procedures at surgery.

Salmonella Typhimurium (S. Typhimurium) infections in pigs constitute a risk for human salmonellosis. The use of probiotics may be a promising tool to reduce Salmonella infections in pigs. The present study investigated the efficacy of Clostridium butyricum (C. butyricum), at two different dosages, as probiotic feed additive against S. typhimurium infection in experimentally challenged pigs. After weaning, 35 Salmonella negative pigs were randomly divided into 4 groups; Negative control: no feed additive (n = 5), Positive control: no feed additive (n = 10), CB-H: +/- 2 x 10(6) CFU C. butyricum/g feed (n = 10), CB-L: +/- 5 x 10(5) CFU C. butyricum/g feed (n = 10). Pigs were fed ad libitum with the experimental feed, including the probiotic feed additive according to the group, from arrival (day-7) until euthanasia (day 42). One week after arrival (day 0), pigs in the positive control group, CB-H and CB-L were orally inoculated with 2 x 108 CFU/mL nalidixic acid resistant S. typhimurium strain 112910a (1 mL/pig). Fecal excretion, serological response, intestinal carriage and prevalence of S. typhimurium positive ileocecal lymph nodes were evaluated. Under the present conditions, the probiotic feed additive C. butyricum did not significantly reduce fecal excretion, serological response, intestinal carriage and prevalence of S. typhimurium in the ileocecal lymph nodes in experimentally challenged pigs. Further research is needed to investigate the results under field conditions and to detect possible additional effects of the application of the probiotic for a longer time period.

Helicobacter suis is a fastidious, Gram negative bacterium that colonizes the stomach of pigs and non-human primates. It has also been associated with gastric disease in humans. A combined agar and broth dilution method was used to analyze the activity of 15 antimicrobial agents against 20 and 15 H. suis isolates obtained from pigs and macaques, respectively. After 48 h microaerobic incubation, minimal inhibitory concentrations (MICs) were determined by software-assisted calculation of bacterial growth as determined by quantitative real-time PCR. A monomodal distribution of MICs was seen for β-lactam antibiotics, macrolides, gentamicin, neomycin, doxycycline, metronidazole, and rifampicin. Presence of a bimodal distribution of MICs indicated that 2 porcine isolates did not belong to the wild type population (WTP) for fluoroquinolones. This was also the case for 1 porcine isolate for tetracycline, 1 porcine and 2 primate isolates for lincomycin, and 1 primate isolate for spectinomycin. Single nucleotide polymorphisms (SNPs) were present in the gyrA gene of the isolates not belonging to the WTP for fluoroquinolones and in ribosomal protein encoding genes of the isolates not belonging to the WTP for tetracycline and spectinomycin. MICs of ampicillin, tetracycline and doxycycline were higher for porcine H. suis isolates compared to primate isolates and in these porcine isolates SNPs were detected in genes encoding penicillin binding and ribosomal proteins. This study indicates that acquired resistance occasionally occurs in H. suis isolates and that zoonotically important porcine isolates may be intrinsically less susceptible to β-lactam antibiotics and tetracyclines than primate isolates.

The aims of this study were to determine whether non-aureus staphylococci (NAS) are present in rectal feces of healthy dairy cows, and if so, to delineate species to which they belong and to study several phenotypic and genotypic traits as a first step toward determining the potential impact of fecal shedding of NAS on bovine udder health. Fecal samples were aseptically collected from the rectum of 25 randomly selected clinically healthy dairy cows in a commercial dairy herd using an automated milking system. Fecal NAS were isolated and then identified at the species level using transfer RNA-intergenic spacer PCR and sequencing of the 16S rRNA housekeeping gene. Strain typing was performed using random amplification of polymorphic DNA (RAPD)-PCR. The antimicrobial resistance profiles, biofilm formation, and growth and inhibitory characteristics of all NAS isolates were evaluated. Half of the cows were shedding NAS, resulting in 31 NAS isolates belonging to 11 different species. The most prevalent species were Staphylococcus rostri (23%, n = 7), Staphylococcus cohnii (16%, n = 5), and Staphylococcus haemolyticus (13%, n = 4) with all Staphylococcus agnetis, Staphylococcus chromogenes, and Staph. rostri isolates belonging to the same strain according to RAPD banding patterns. Acquired antimicrobial resistance was observed in 28 of the 31 NAS isolates, mainly due to β-lactamase production. Most of the isolates (84%, n = 27) had a weak biofilm-forming potential, but only 2 contained the bap gene. The ica and aap genes were not detected in any of the isolates. In vitro growth of Staphylococcus aureus and Streptococcus dysgalactiae was inhibited by Staph. agnetis isolates, and Staph. chromogenes isolates were able to inhibit the growth of Strep. dysgalactiae and Streptococcus uberis. All fecal isolates were able to grow when oxygen and iron were limitedly available, mimicking the growth conditions in the mammary gland.

Subclinical infections with Salmonella Typhimurium occur frequently in pigs. They constitute a risk for human salmonellosis and are difficult to control with currently available control measures. Vaccination against Salmonella Typhimurium in pigs can be an effective tool to control Salmonella infections at farm level. In the present study, the efficacy of an attenuated Salmonella Typhimurium vaccine (Salmoporc®, IDT Biologika) to control Salmonella infections in pigs was evaluated in three subclinically infected pig herds. The effect on Salmonella excretion and the number of pigs positive for Salmonella Typhimurium field and vaccine strains in ileocecal lymph nodes at slaughter were evaluated using five different vaccination strategies: 1. vaccination of sows, 2. vaccination of sows and piglets, 3. vaccination of sows and fattening pigs, 4. vaccination of piglets, 5. vaccination of fattening pigs, which were all compared to a non-vaccinated control group (experimental group 6). Each vaccination strategy was implemented in each farm, during two consecutive production cycles of the same sows. The prevalence of Salmonella Typhimurium field strain excretion was low; in total, 4% of the fecal and overshoe samples collected in the non-vaccinated control group were Salmonella Typhimurium field strain positive. The excretion of Salmonella Typhimurium field strain did not significantly differ between farms, production cycles and experimental groups. Applying vaccination in either sows and piglets, sows and fattening pigs, or in piglets only, resulted in a significantly reduced number of Salmonella Typhimurium field strain positive lymph nodes of slaughter pigs in the second production cycle, but not in the first production cycle. Vaccination of sows and piglets resulted in the most consistent reduction of Salmonella Typhimurium field strain positive lymph nodes at slaughter. The vaccine strain was detected in the lymph nodes of 13 pigs at slaughter, indicating the possible persistence of the vaccine strain until slaughter. Because of limitations in the study design, and the variability between farms and production cycles, the results of the current observational study should be extrapolated with care. Nevertheless, the results provide evidence that applying vaccination against Salmonella Typhimurium in sows and piglets (preferred), sows and fattening pigs, and piglets only can support the control of Salmonella Typhimurium infections by decreasing the prevalence of Salmonella Typhimurium field strain positive lymph nodes at slaughter.

Vaccination of pigs against Salmonella Typhimurium (S. Typhimurium) can be effective for the control of Salmonella infections at the farm level and reduce the risk of Salmonella contamination in the food chain. However, vaccination may interfere with herd serological status in serology-based Salmonella monitoring programs. The present study investigated the effects of an attenuated S. Typhimurium vaccine (Salmoporc, IDT Biologika) on Salmonella serology in sows, neonatal piglets and slaughter pigs from three subclinically infected herds. Within each herd, five different vaccination protocols were tested as follows: group 1, vaccination of sows; group 2, vaccination of sows and piglets; group 3, vaccination of sows and fattening pigs; group 4, vaccination of piglets; and group 5 vaccination of fattening pigs. Each group was compared to a non-vaccinated control group (group 6). Sera were analyzed by ELISA (HerdChek Swine Salmonella, IDEXX Laboratories) and sample-to-positive (S/P) ratios were calculated. At day 3 after farrowing, but not before vaccination, S/P ratios in vaccinated sows (mean: 2.21) were significantly higher than S/P ratios in non-vaccinated sows (mean: 0.87, P<0.001). S/P ratios in 3-day old piglets from vaccinated sows (mean: 2.46) were significantly higher than S/P ratios in similar piglets from non-vaccinated sows (mean: 0.73, P<0.001). At slaughter, S/P ratios in pigs from groups 2, 3, 4 and 5 were significantly higher than those in the non-vaccinated control group (P<0.001). Therefore, vaccination of piglets and fattening pigs could have implications for current serology-based Salmonella monitoring programs in slaughter pigs.

Different mycobacterial species are encountered in bovine medicine. The fastidiously growing mycobacteria (Mycobacterium bovis as the cause of bovine tuberculosis, and Mycobacterium avium ssp. paratuberculosis, MAP, as the cause of paratuberculosis) are well known and targeted in eradication/control or monitoring programs in different countries, whereas the rapidly growing species is only rarely identified from bovine disease. The latter have occasionally been reported as the cause of bovine clinical mastitis, but recent reports are scarce. In this study, Mycolicibacterium smegmatis (basonym Mycobacterium smegmatis) was identified as cause of granulomatous, relapsing clinical mastitis in 2 cows from one Belgian dairy herd. Milk, blood, and fecal samples were collected, as well as tissue samples after the cows were culled. Serological analysis conducted on milk and serum samples resulted in positive reactions for MAP, but negative for Mycobacterium bovis. Production of IFN-γ showed sensitization with mycobacteria or similar organisms, other than M. bovis, in one cow. Detection of MAP by bacteriological culture and IS900-based quantitative PCR on milk and feces remained negative. In conclusion, this paper describes M. smegmatis as a cause of bovine clinical mastitis in Belgium and suggests cross-reactivity of the intramammary M. smegmatis infection with routinely used serological tests for MAP.

The objective of this study was to compare qualitatively and quantitatively the results of identification of the bacteria present in milk samples from cows with subclinical mastitis using multiplex qPCR assay and matrix‐assisted laser desorption‐ionization time of flight mass spectrometry (MALDI‐TOF MS®) after bacteriological growth.

In a horse with severe sweet itch and a history of corticosteroid treatment for this disorder, a single, well-circumscribed and crusty white lesion was present on the thigh. The geophilic dermatophyte species M. gypseum was cultured from the lesion. The lesion was treated topically once a week with an enilconazole emulsion for four weeks. Full recovery was noted after two months. This case suggests that sweet itch combined with systemic corticosteroid treatment, may act as predisposing factor for dermatophyte infection. In addition, the importance of correct isolation and identification of the causal agent is highlighted.