Prevalence of Mastitis and Brucellosis in Cattle in Awassa and the Peri‐Urban Areas of Two Smaller Towns

The prevalence of mastitis and brucellosis in urban and peri‐urban settings was studied in Awassa and two smaller nearby towns in southern Ethiopia, because milk‐born diseases are causing a risk for human health, besides direct impacts on animal production. Mastitis was investigated by examining 80 cows (320 udder quarters) using California mastitis test (CMT) and somatic cell count (SCC). The prevalence of brucellosis was assessed by sampling 177 cattle in Awassa and its peri‐urban areas using serological methods. Logistic regression was used to analyse risk factors associated with mastitis. Prevalence of clinical mastitis on quarter level was 0.9%, and 1.9% of quarters were non‐functional or blocked. Prevalence of sub‐clinical mastitis at quarter level in urban and peri‐urban areas was significantly different (P < 0.05). Cows in large herds and at advanced lactation number were associated with higher risk of infection. The percentage of quarters positive on CMT (42.5%) was close to the percentage‐positive detected by SCC (41.2%). Prevalence of brucellosis was 3.9% in the peri‐urban area, while no brucellosis cases were detected in Awassa. More frequent use of artificial insemination in the urban than in peri‐urban area might have contributed to the absence of brucellosis in the urban location. The extent of mastitis is, however, a threat to the dairy enterprise in and around Awassa. Pasteurization of milk and milk products is indicated in some parts of the area because of the danger of brucellosis.     

Exfoliation rate of mammary epithelial cells in milk on bovine mastitis caused by Staphylococcus aureus is associated with bacterial load

The exfoliation rate of mammary epithelial cells (MECs) in milk is affected by physiological, breeding and environmental factors. Little is known about the relationship between the MEC exfoliation into milk and mammary‐infected Staphylococcus aureus (S. aureus) load on bovine mastitis caused by S. aureus. The aim of this study was to investigate the relationship between S. aureus load and the proportion of MEC exfoliation in milk using five substantial bovine mastitis models. In 64 randomly extracted milk samples from udders at 3–21 days after S. aureus infusion, there were various samples with different numbers of S. aureus counts and somatic cell counts. No significant correlations were found between the S. aureus counts and somatic cell count (r = 0.338). In contrast, a significant correlation was noted between S. aureus counts and the proportion of cytokeratin‐positive cells in the milk from the infused udders (r = 0.734, P < 0.01). In conclusion, the increasing MEC exfoliation rate in milk from mastitis udders caused by S. aureus may contribute to reduced milk yield.     

Methicillin‐Resistant Staphylococcus aureus from Brazilian Dairy Farms and Identification of Novel Sequence Types

The aim of this study was to investigate the phenotypic and genotypic diversity and anti‐microbial resistance among staphylococci of dairy herds that originated from Paraiba State, north‐eastern Brazil, a region where such studies are rare. Milk samples (n = 552) were collected from 15 dairy farms. Isolates were evaluated for anti‐microbial susceptibility by Kirby–Bauer disc diffusion method. Confirmation of methicillin‐resistant Staphylococcus aureus (MRSA) was performed using multiplex PCR targeting mecA and nuc genes in addition to phenotypic assay based on PBP‐2a latex agglutination. Clonal relatedness of isolates was determined by pulsed‐field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) genotyping. Staphylococci were detected in 269 (49%) of the samples. Among these, 65 (24%) were S. aureus. The remaining 204 isolates were either coagulase‐negative staphylococci (n = 188; 70%) or coagulase positive other than S. aureus (n = 16; 6%). Staphylococci were cultured in seven (35%) of the 20 hand swab samples, from which five isolates were S. aureus. The isolates were most commonly resistant against penicillin (43%), ampicillin (38%) and oxacillin (27%). The gene mecA was detected in 21 S. aureus from milk and in one isolate from a milker's hand. None of the isolates were resistant to vancomycin. PFGE findings showed high clonal diversity among the isolates. Based on MLST, we identified a total of 11 different sequence types (STs 1, 5, 6, 83, 97, 126, 1583, 1622, 1623, 1624 and 1625) with four novel STs (ST1622‐ST1625). The findings show that MRSA is prevalent in milk from semi‐extensive dairy cows in north‐eastern Brazil, and further investigation on its extent in various types of milk production systems and the farm‐to‐table continuum is warranted.     

Role,ownership and presence of domestic animals in peri‐urban households of Kisumu,Kenya

Low‐ and middle‐income countries are experiencing rapid urban population growth, particularly in peri‐urban informal settlements. In these urban areas, animal husbandry remains a valuable source of income and protein‐rich foods but may also present a risk of zoonotic disease threat. To date, there have been studies that have assessed the prevalence and nature of animal ownership in these communities. This cross‐sectional survey assessed the geographical, sociocultural and economic factors behind the presence, ownership and purpose of domestic animals in three informal peri‐urban communities of Kisumu, Kenya. A majority (n = 587) of the study households exhibited domestic animal presence in the living space yet only 32% of households reported animal ownership (n = 252). The purposes of ownership included: for meat/eggs (55%); for income, sale or trade (43%); for milk production (31%); and as companions/pets (31%). Among households that owned animals, 76% reported that at least one animal slept in the house at night. In multivariate logistic regression, the following factors were significantly associated with household animal ownership: ownership of agricultural land (OR = 1.94, 95% CI = 1.12, 3.35), perceiving a strong community bond (OR = 2.28, 95% CI = 1.25, 4.16), and household membership in a community group (OR = 1.64, 95% CI = 1.04, 2.60). This research demonstrates the high prevalence of animal ownership in a low‐income and high‐density peri‐urban neighbourhood of an African city, which may facilitate zoonotic disease transmission. Further research should assess if and to what extent animal ownership in such communities is associated with disease risk.     

Multidrug‐Resistant Outbreak‐Associated Salmonella Strains in Irrigation Water from the Metropolitan Region,Chile

Salmonella enterica (S. enterica) is the main cause of foodborne diseases in the Chilean population. With the aim of characterizing the presence of S. enterica in bodies of water, samples from 40 sources were obtained, including rivers and irrigation canals used by agricultural farms in the most populated regions of Chile. As result, 35 S. enterica isolates belonging to several serotypes were detected, with the highest frequency represented by Typhimurium and Enteritidis. All strains showed phenotypic antimicrobial resistance, and most of them were multiresistant to critically important antimicrobials. In addition, the pulse‐field gel electrophoresis analysis using XbaI and BlnI endonucleases showed that seven Salmonella isolates belonging to serotypes Typhimurium, Enteritidis and Infantis had identical pulsotypes to outbreak‐associated clinical isolates detected in the Chilean population, suggesting a public health risk of water pollution in this region. Among sampling sites, the higher detection rates were observed in rural than urban and peri‐urban areas, suggesting that the animal husbandry might contribute for environmental dispersion of this pathogen. Future efforts should address the characterization of cause‐and‐effect relationship between water contamination and foodborne disease, including the implementation of surveillance programmes to tackle potential risks for both human and animal populations.     

Impact of a trace element supplementation programme on health and performance of cross‐breed (Bos indicus x Bos taurus) dairy cattle under tropical farming conditions: a double‐blinded randomized field trial

Small‐scale urban dairy farms (n = 16) in and around Jimma, Ethiopia with cross‐bred (Bos indicus × Bos taurus) cows were enrolled in a double‐blinded intervention study to investigate the effect of a trace element supplementation programme on trace element status and milk concentrations as well as performance [body condition score (BCS), milk yield, leptin], milk composition, antioxidant status (ferric‐reducing ability of plasma (FRAP), thiobarbituric acid‐reactive substances (TBARS)], blood biochemistry, serum proteins and immune response (antibody titre upon rabies vaccination). The farms were allocated to a (1) placebo or (2) Cu, Zn, Se, Co and I supplementation treatment for 150 d. On days 0 and 120, four lactating cows per farm were sampled for milk and plasma, and on day 150 for serum, following primo‐vaccination. Cu deficiency was present in 17% and marginal Se deficiency in 30% of initially sampled cows, while no Zn shortage was detected. Over 120 days, trace element supplementation caused a bigger increase in plasma Se and Cu concentrations, but also a larger decrease of plasma Fe concentrations. A larger increase in milk Se concentrations was observed in the supplemented group, whereas none of the other elements were affected. BCS decreased more over time in the supplemented group. None of the other parameters of performance and antioxidant status nor milk composition or blood biochemistry was affected by treatment. Antibody response to rabies vaccination did not differ between groups, whereas α1‐globulins tended to be lower and β‐globulins tended to be higher in the supplemented group. In conclusion, despite improved Cu and Se status and Se concentrations in milk, cows on tropical urban dairy farms did not seem to benefit from trace element supplementation, with respect to the parameters investigated.     

MicroRNA‐145 regulates immune cytokines via targeting FSCN1 in Staphylococcus aureus‐induced mastitis in dairy cows

Dairy cow mastitis is a detrimental factor in milk quality and food safety. Mastitis generally refers to inflammation caused by infection by pathogenic microorganisms. Our studies in recent years have revealed the role of miRNA regulation in Staphylococcus aureus‐induced mastitis. In the present study, we overexpressed and suppressed miR‐145 to investigate the function of miR‐145 in Mac‐T cells. Flow cytometry, ELISA and EdU staining were used to detect changes in the secretion of several Mac‐T cytokines and in cell proliferation. We found that overexpression of miR‐145 in Mac‐T cells significantly reduced the secretion of IL‐12 and TNF‐α, but increased the secretion of IFN‐γ; the proliferation of bovine mammary epithelial cells was also inhibited. Using quantitative real‐time PCR (qRT‐PCR), Western blotting and luciferase multiplex verification techniques, we found that miR‐145 targeted and regulated FSCN1. Knock‐down of FSCN1 significantly increased the secretion of IL‐12, while the secretion of TNF‐α was significantly downregulated in Mac‐T cells. Upon S. aureus infection of mammary gland tissue, the body initiated inflammatory responses; Bta‐miR‐145 expression was downregulated, which reduced the inhibitory effect on the FSCN1 gene; and upregulation of FSCN1 expression promoted mammary epithelial cell proliferation to allow the recovery of damaged tissue. The results of the present study will aid in understanding the immune mechanism opposing S. aureus infection in dairy cows and will provide a laboratory research basis for the prevention and treatment of mastitis.     

Husbandry Factors and the Resumption of Luteal Activity in Open and Zero‐Grazed Dairy Cows in Urban and Peri‐Urban Kampala,Uganda

The study investigated the influence of selected husbandry factors on interval to resumption of post‐partum cyclicity among dairy cows in urban and peri‐urban Kampala. A prospective study of 85 day post‐partum period of 59 dairy cows in open (n = 38) and zero grazing (n = 21) systems was conducted on 24 farms. Cows of parity 1–6 were recruited starting 15–30 days post‐partum. Progesterone (P4) content in milk taken at 10–12 day intervals was analysed using ELISA. The cow P4 profiles were classified into ‘normal’ (< 56 days), ‘delayed’ (> 56 days), ‘ceased’ or ‘prolonged’ (if started < 56 days but with abnormal P4 displays) resumption of luteal activity and tested for association with husbandry and cow factors. Of the 59 cows, luteal activity in 81.4% resumed normally and in 18.6%, delayed. Only 23.7% maintained regular luteal activity, while the others had ceased (10.2%), prolonged (37.3%) or unclear luteal activity (20.3%). There were no differences between open and zero‐grazed cows. Milk production was higher (p < 0.05) in zero than open grazing, in urban than peri‐urban and in cows fed on brew waste (p < 0.001) compared with mill products and banana peels. Results suggest that luteal activity resumes normally in a majority of cows, although only a minority experienced continued normal cyclicity once ovulation had occurred, in the two farming systems irrespective of feed supplements or water, and that supplementing with brew waste is beneficial for milk production.     

Clostridioides difficile on Ohio swine farms (2015): A comparison of swine and human environments and assessment of on‐farm risk factors

Swine are known reservoirs for Clostridioides difficile, formerly known as Clostridium difficile, and transmission from swine to human farm workers is strongly suggested by previous studies. This cross‐sectional study evaluated the potential role of farm environmental surfaces, including those in worker breakrooms and swine housing areas, in the possible transmission of C. difficile from swine to farm workers. Environmental surfaces and piglet faeces at 13 Ohio swine farms were sampled in 2015. Typical culturing techniques were performed to isolate C. difficile from samples, and amplification of toxin genes (tcdA, tcdB and cdtB) and PCR‐ribotyping were used to genetically characterize recovered isolates. In addition, sequencing of toxin regulatory gene, tcdC, was done to identify the length of identified deletions in some isolates. A survey collected farm‐level management risk factor information. Clostridioides difficile was recovered from all farms, with 42% (188/445) of samples testing positive for C. difficile. Samples collected from all on‐farm locations recovered C. difficile, including farrowing rooms (60%, 107/178), breakrooms (50%, 69/138) and nursery rooms (9%, 12/129). Three ribotypes recovered from both swine and human environments (078, 412 and 005) have been previously implicated in human disease. Samples taken from farrowing rooms and breakrooms were found to have greater odds of C. difficile recovery than those taken from nursery rooms (OR = 40.5, OR = 35.6, p < .001 respectively). Farms that weaned ≥23,500 pigs per year had lower odds of C. difficile recovery as compared to farms that weaned fewer pigs (OR = 0.4, p = .01) and weekly or more frequent cleaning of breakroom counters was associated with higher odds of C. difficile recovery (OR = 11.7, p < .001). This study provides important insights into the presence and characterization of C. difficile found in human environments on swine farms and highlights how these areas may be involved in transmission of C. difficile to swine farm workers and throughout the facility.     

Peri‐conceptional under‐nutrition alters the expression of TRIM28 and ZFP57 in the endometrium and embryos during peri‐implantation period in domestic pigs

DNA methylation is maintained by the main elements of methylation complex—tripartite motif containing 28 (TRIM28) and zinc finger protein 57 (ZFP57). Previously, it was found that the activity of TRIM28 and ZFP57 determines the process of DNA methylation and preserves over‐expression of genes. We hypothesized that restricted diet applied during peri‐conceptional period may induce changes in the expression of methylation complex in porcine endometrium and embryos during the peri‐implantation period. The aim of this study was to detect and determine the expression of TRIM28 and ZFP57 in the endometrium and embryos harvested from gilts during the peri‐implantation period (days 15–16 of pregnancy) fed restricted (n = 5) or normal (n = 5) diet during peri‐conceptional period. In restricted‐diet‐fed gilts, endometrial expression of TRIM28 and ZFP57 mRNAs was decreased in comparison with normal‐diet‐fed gilts (p ≤ .01), while the embryonic expression of TRIM28 and ZFP57 mRNAs was increased in restricted‐diet‐fed gilts (p ≤ .05). The immunofluorescence showed the presence of TRIM28 and ZFP57 in luminal epithelial (LE), glandular epithelial (GE) and stromal cells (ST) of the endometrium as well as in the embryos. Total endometrial and embryonic abundance of TRIM28 and ZFP57 proteins was significantly higher (p ≤ .05) in restricted‐diet‐fed gilts than in normal‐diet‐fed gilts. Female under‐nutrition during peri‐conceptional period affects the expression of two main elements of methylation complex in the endometrium and in embryos during the peri‐implantation period and may have the impact on DNA methylation in these tissues.     

Influence of On‐farm pig Salmonella status on Salmonella Shedding at Slaughter

The risk of Salmonella shedding among pigs at slaughter with regard to their previous on‐farm Salmonella status was assessed in a group of pigs from a farm from NE of Spain. A total of 202 pigs that had been serologically monitored monthly during the fattening period and from which mesenteric lymph nodes (MLN) and faecal (SFEC) samples were collected at slaughter for Salmonella isolation were included. A repeated‐measures anova was used to assess the relationship between mean OD% values during the fattening period and sampling time and bacteriology on MLN and SFEC. Pigs were also grouped into four groups, that is pigs seronegative during the fattening period and Salmonella negative in MLN (group A; n = 69); pigs seronegative during the fattening period but Salmonella positive in MLN (B; n = 36); pigs seropositive at least once and Salmonella positive in MLN (C; n = 50); and pigs seropositive at least once but Salmonella negative in (D; n = 47). Pigs shedding at slaughter seroconverted much earlier and showed much higher mean OD% values than non‐shedders pigs. The proportion of Salmonella shedders in groups A and D was high and similar (26.1% and 29.8%, respectively), but significantly lower than that for groups B and C. The odds of shedding Salmonella for groups B and C were 4.8 (95% CI = 1.5–15.5) and 20.9 (3.7–118) times higher, respectively, when compared to A. It was concluded that a large proportion of Salmonella seronegative pigs may shed Salmonella at slaughter, which would be likely associated to previous exposure with contaminated environments (i.e. transport and lairage). For pigs already infected at farm, the likelihood of shedding Salmonella was much higher and may depend on whether the bacterium has colonized the MLN or not. The odds of shedding Salmonella spp. were always much higher for pigs in which Salmonella was isolated from MLN.     

Effect of nutrient levels during the far‐off period on postpartum productivity in dairy cows

The present study aimed to determine the effects of differing nutrient levels during the far‐off period on postpartum metabolism and milk production in lactating cows. Twenty‐six multiparous cows were assigned to three dietary treatments in the far‐off period: a low‐energy diet (L, n = 9, 80% intake of the total digestible nutrients requirement), a moderate‐energy diet (M, n = 8, 105%) and a high‐energy diet (H, n = 9, 130%). During the close‐up period, all cows were provided with 105% intake. After parturition, all cows were fed a lactation diet. The BCS recovery was slow, and low milk yield was found in the H group. In the L group, BCS recovery was favorable after parturition, and lactation persistence was increased. The L group had low rumen endotoxin activity and a high initial ovulation rate after parturition. These findings indicate that a high‐energy diet during the far‐off period has a deleterious effect on milk production. In contrast, the restricted diet in the far‐off period increased adaptability with respect to peri‐parturition metabolic changes, improved the post‐parturition nutritional state, and increased milk production. Furthermore, it suggests that the nutrient levels in the far‐off period affect rumen endotoxin activity and reproductive function after parturition.     

The Ability of the Enzyme‐Linked Immunosorbent Assay to Detect Antibody against Staphylococcus aureus in Milk following Experimental Intramammary Infection

Changes in the milk antibody levels against Staphylococcus aureus were measured at the start of an experimental intramammary instillation of either S. aureus (Study I) or Staphylococcus hyicus (Study II). A commercial enzyme‐linked immunosorbent assay system was used. Twenty‐one Holstein cows were enrolled in Study I and 15 Holstein cows were used in Study II. Pathogen instillation began 21 days before the start of the non‐lactating period. Cows received intramammary antibiotic treatment in all quarters immediately after the last milking, the start of the non‐lactating period. Lacteal secretions were collected before the start of the non‐lactating period, and during the immediate postpartum period in both studies, and during the non‐lactating period in Study I. Milk was cultured for mastitis pathogens and S. aureus antibody levels and somatic cell counts were determined from all samples. There was an approximate 2‐week delay in the elevation in antibody levels in response to the instillation of S. aureus. Antibody levels remained elevated in cows with S. aureus intramammary infections postpartum, but were below threshold in cows where intramammary infections were cured during the non‐lactating period. Antibody levels were elevated by S. hyicus intramammary infections, remained elevated for the first 12 days postpartum, but were below threshold by day 21 postpartum. Cows with incipient intramammary S. aureus infections might be misclassified as false negatives by the antibody test. However, results suggest that cows with S. hyicus intramammary infections that were not cured would not be misclassified if milk is withheld from test for the first 30 days postpartum, as recommended by the manufacturer of the test.     

Urban Prevalence of Listeria spp. and Listeria monocytogenes in Public Lavatories and on Shoe Soles of Facility Patrons in the European Capital City Vienna

The aim of this study was to determine the prevalence of Listeria spp. and Listeria monocytogenes (L. monocytogenes) in urban public lavatories and on shoe soles of facility patrons in a European capital city. More than 91% of all municipal public lavatories in Vienna close to public hubs were included in this study. Overall, 373 swab samples of public lavatories and shoes of facility patrons were enriched, according to ISO 11290‐1. Listeria monocytogenes isolates were subtyped using pulsed‐field gel electrophoresis. A total of 24 samples were positive for Listeria spp., yielding an overall prevalence of 6.4% (24/373). Listeria monocytogenes was found in 2.1% (8/373) of all samples. Swabs from lavatories in parks, container lavatories and lavatories at markets had the highest prevalences of 20.7% (6/29), 20% (2/10) and 12.5% (1/8) Listeria spp., respectively. These detection rates were statistically significantly higher than those associated with lavatories in shopping centres (P = 0.003, P = 0.002, P = 0.02) and at public transport locations (P = 0.0004, P = 0.005, P = 0.02). Shoes sampled at Christmas markets showed the highest Listeria spp. and L. monocytogenes prevalences of 80% (4/5) and 40% (2/5), respectively. With regard to shoe type, Listeria spp. detection rates were 14.3% (3/21; winter boots), 13.3% (2/15; hiking boots), sport shoes (5.9%; 2/34) and brogues (5.1%; 4/79). No Listeria spp. were found on shoe soles that had smooth treads (0/76), while Listeria spp. were detected on 19.5% (8/41) of medium depth tread shoe types and on 9.4% (3/32) of deep tread shoes. These data suggest that soil environment is still one of the most important reservoirs for the foodborne pathogen L. monocytogenes.     

Genome analysis of methicillin‐resistant Staphylococcus aureus isolated from pigs: Detection of the clonal lineage ST398 in Cameroon and South Africa

Food animals are considered reservoirs of methicillin‐resistant Staphylococcus aureus (MRSA) and are implicated in their zoonotic transmission in the farm‐to‐plate continuum. LA‐MRSA has been reported as a zoonotic agent that has the potential to spread to humans and may cause infections in at‐risk groups. In this study, whole genome sequencing was used to describe the genetic environment (resistance mechanisms, virulence factors and mobile genetic elements) and investigate the genetic lineages of MRSA isolates from pigs in Cameroonian and South African abattoirs. During March–October 2016, 288 nasal and rectal pooled samples from 432 pigs as well as nasal and hand swabs from 82 humans were collected. Genomic DNA was sequenced using an Illumina MiSeq platform. Generated reads were de novo‐assembled using the Qiagen CLC Genomics Workbench and SPAdes. The assembled contigs were annotated, and antibiotic resistance genes, virulence factors, plasmids, SCCmec and phage elements were identified with ResFinder, Virulence Finder, PlasmidFinder, SCCmec Finder and PHAST, respectively. Core genome single nucleotide analysis was undertaken to assess clonal relatedness among isolates. A lower MRSA prevalence was observed in pigs in Cameroon (n = 1/13; 0.07%) compared with South Africa (n = 4/22; 18.18%), and none of the workers were colonized by MRSA. Genome analysis identified various antibiotic resistance genes along with six virulence factors in all isolates. All MRSA isolates belonged to the clonal lineage ST398 (spa‐type t011) and harboured the type Vc SCCmec and several plasmids. Our study shows that the livestock‐associated MRSA clonal lineage ST398 is already present in both Cameroon and South Africa and is probably underestimated in the absence of molecular epidemiological studies. It reveals the serious food safety and public health threat associated with this animal strain and underscores the need for interventions to contain this resistant clone.     

The occurrence of Salmonella,extended‐spectrum β‐lactamase producing Escherichia coli and carbapenem resistant non‐fermenting Gram‐negative bacteria in a backyard poultry flock environment

Increase in the number of small‐scale backyard poultry flocks in the USA has substantially increased human‐to‐live poultry contact, leading to increased public health risks of the transmission of multi‐drug resistant (MDR) zoonotic and food‐borne bacteria. The objective of this study was to detect the occurrence of Salmonella and MDR Gram‐negative bacteria (GNB) in the backyard poultry flock environment. A total of 34 backyard poultry flocks in Washington State (WA) were sampled. From each flock, one composite coop sample and three drag swabs from nest floor, waterer‐feeder, and a random site with visible faecal smearing, respectively, were collected. The samples were processed for isolation of Salmonella and other fermenting and non‐fermenting GNB under ceftiofur selection. Each isolate was identified to species level using MALDI‐TOFF and tested for resistance against 16 antibiotics belonging to eight antibiotic classes. Salmonella serovar 1,4,[5],12:i:‐ was isolated from one (3%) out of 34 flocks. Additionally, a total of 133 ceftiofur resistant (Cef^R) GNB including Escherichia coli (53), Acinetobacter spp. (45), Pseudomonas spp. (22), Achromobacter spp. (8), Bordetella trematum (1), Hafnia alvei (1), Ochrobactrum intermedium (1), Raoultella ornithinolytica (1), and Stenotrophomonas maltophilia (1) were isolated. Of these, 110 (82%) isolates displayed MDR. Each flock was found positive for the presence of one or more Cef^R GNB. Several MDR E. coli (n = 15) were identified as extended‐spectrum β‐lactamase (ESBL) positive. Carbapenem resistance was detected in non‐fermenting GNB including Acinetobacter spp. (n = 20), Pseudomonas spp. (n = 11) and Stenotrophomonas maltophila (n = 1). ESBL positive E. coli and carbapenem resistant non‐fermenting GNB are widespread in the backyard poultry flock environment in WA State. These GNB are known to cause opportunistic infections, especially in immunocompromised hosts. Better understanding of the ecology and epidemiology of these GNB in the backyard poultry flock settings is needed to identify potential risks of transmission to people in proximity.     

Randomized clinical trial to evaluate the effectiveness of enrofloxacin as a second‐line antibiotic for treatment of acute Escherichia coli mastitis

The objective of the present study was to evaluate the effectiveness of enrofloxacin (ERFX) as a second‐line antibiotic for treatment of acute Escherichia coli (E. coli) mastitis. Forty‐two cows with naturally occurring acute E. coli mastitis were enrolled. On the first day of treatment (day 0), empirically selected antibiotics (oxytetracycline: n = 32, kanamycin: n = 10) were administered. Although systemic signs improved in 10 cows (first‐line group), the signs remained unchanged or worsened in 32 cows on day 1, including two cows that were found dead. The 30 surviving cows were randomly assigned to second‐line groups constituting an ERFX group (n = 19) or a control group (n = 11) that was treated with other antibiotics. Response to each treatment was evaluated by measuring clinical signs from day 0 to day 3, subsequent quarter milk recovery, and the 60‐day survival rate. Appetite on day 3 was significantly better in the ERFX group compared to the control group. No significant differences were observed in the 60‐day survival rate or the subsequent milk recovery between the ERFX group and the control group. Thus, the use of ERFX as a second‐line antibiotic for the treatment of acute E. coli mastitis could induce a rapid appetite recovery.     

Evaluating the risk of tick‐borne relapsing fever among occupational cavers—Austin,TX, 2017

Tick‐borne relapsing fever (TBRF) is a potentially serious spirochetal infection caused by certain species of Borrelia and acquired through the bite of Ornithodoros ticks. In 2017, Austin Public Health, Austin, TX, identified five cases of febrile illness among employees who worked in caves. A cross‐sectional serosurvey and interview were conducted for 44 employees at eight organizations that conduct cave‐related work. Antibodies against TBRF‐causing Borrelia were detected in the serum of five participants, four of whom reported recent illness. Seropositive employees entered significantly more caves (Median 25 [SD: 15] versus Median 4 [SD: 16], p = 0.04) than seronegative employees. Six caves were entered more frequently by seropositive employees posing a potentially high risk. Several of these caves were in public use areas and were opened for tours. Education of area healthcare providers about TBRF and prevention recommendations for cavers and the public are advised.     

Effects of butyrate supplementation in antibiotic‐free milk replacer and starter on growth performance in suckling calves

The aim of this study was to evaluate butyrate supplementation of antibiotic‐free milk replacer and starter on growth performance in male Holstein calves. Twenty‐nine calves were divided into two groups. Group C (n = 13) was fed antibiotic‐free milk replacer without supplementation, and Group B (n = 16) was fed antibiotic‐free milk replacer supplemented with butyrate (1.6 % DM of Gustor BP70^®). Starter in Group B contained 0.3 % DM of Gustor BP70^®. The intake of milk replacer was lower in group B than in C (p = 0.07 for the treatment x week interaction). Body weight (BW) and heart girth (HG) in group B was higher than in C during the experimental period (p = 0.07 and 0.01 for the treatment × week interaction, respectively). The duration of the weaning period in group B was shorter than in group C (p = 0.02). β‐hydroxybutyrate (BHBA) was higher in group B than in C (p = 0.04). Insulin like growth factor‐1 (IGF‐1) concentrations tended to be higher in group B than in C (p = 0.07 for treatment × week interaction). Our results show that butyrate supplementation in antibiotic‐free milk replacer and starter exerted positive effects on growth performance in suckling calves.     

Real‐time quantitative PCR‐based detection of Coxiella burnetii in unpasteurized cow's milk sold for human consumption

Coxiella burnetii is a zoonotic pathogen with a worldwide distribution that is responsible for Q fever in humans. It is a highly infectious bacterium that can be transmitted from cattle to humans through the consumption of unpasteurized milk. We report the molecular identification of C. burnetii in raw cow's milk being sold directly for human consumption in Brazil without official inspection or pasteurization. One hundred and twelve samples of raw milk were analysed by real‐time quantitative PCR (qPCR), and C. burnetii was detected in 3.57% (4/112) of the samples at a concentration ranging from 125 to 404 bacteria per millilitre. The identification of this zoonotic pathogen in raw milk sold directly for human consumption is a public health concern since C. burnetii can be transmitted through the oral route. This result indicates that health education and other preventive measures should be officially implemented in Brazil to prevent the spread of infection. To our knowledge, this is the first qPCR‐based detection of C. burnetii in raw milk samples from cows sold in Brazil that do not undergo official inspection or pasteurization.