Search

Aims: Cattle are a known main reservoir for acid-resistant Escherichia coli O157 and Salmonella enterica serovar Typhimurium DT104. We studied the response of S. Typhimurium DT104 to extreme low pH environments and compared their response to that of acid-resistant E. coli O157 and other S. Typhimurium phage types. Methods and Results: Bacteria were grown in nutrient-rich medium and subsequently acid challenged at pH 2.5. We found that stationary phase cultures of various S. Typhimurium strains were able to survive a challenge for 2 h at pH 2.5. As in E. coli, the ability of S. Typhimurium to survive at pH 2.5 was shown to be dependent on the presence of amino acids, specifically arginine. The amount of proton pumping H[sup +]/ATPase, both in E. coli O157 and S. Typhimurium strains, was lower when grown at pH values <6 than after growth at pH 7.5. Cyclo fatty acid content of membranes of bacteria grown at pH values <6 was higher than that of membranes of bacteria grown at pH 7.5. Conclusions: Various S. Typhimurium strains, both DT104 and non-DT104, are able to survive for a prolonged period of time at pH 2.5. Their response to such low pH environment is seemingly similar to that of E. coli O157. Significance and Impact of the Study: Food-borne pathogens like S. Typhimurium DT104 and E. coli O157 form a serious threat to public health since such strains are able to survive under extreme low pH conditions as present in the human stomach. The emergence these acid-resistant strains suggests the presence of a selection barrier. The intestinal tract of ruminants fed a carbohydrate-rich diet might be such a barrier. [ABSTRACT FROM AUTHOR]

The study focused on the performance of selected sampling methods for recovery of: (a) marker organism (nalidixic acid resistant E. coli K12) topically inoculated onto hide of experimental cattle (to achieve >6log10 CFU/cm2), and (b) naturally occurring microflora from hide of experimental cattle. Recoveries of bacteria by each of five consecutive passes using wet sponge swabbing of the hide was determined, and compared with bacteria remaining on the hair (recovered by taking hair-clippings). These results showed that: (i) the highest recovery (5.52log10 CFU/cm2) of the topically inoculated marker organism was achieved by the first pass of the wet sponge swabbing technique, (ii) significant levels of the marker organism (5.15log10 CFU/cm2) remained on the hair even after five consecutive swabbing passes, and (iii) the highest recovery of natural flora (from non-inoculated hide) was achieved by the hair-clipping sampling technique.Recoveries of both the marker organism (topically inoculated on hide) and the natural flora (non-inoculated hide) by each of the three hide sampling techniques used (single-pass wet swab, wet–dry swab, and electric hair-clipping) were determined. The results showed that: (i) the efficacy of the hide sampling techniques in recovery of topically inoculated marker organism was in the order: wet–dry swabbing > single-pass wet swabbing > hair-clipping, and (ii) the efficacy of the sampling techniques in recovery of natural flora from non-inoculated hide was, in the order of the highest to lowest efficiency; hair-clipping > wet–dry swabbing > single-pass wet swabbing. From a practical perspective of the microbiological monitoring of hide under commercial abattoir conditions, swabbing techniques are more acceptable than clipping techniques. However, further research is necessary to optimise and validate microbiological sampling techniques for animal coats. [Copyright &y& Elsevier]

The hide of cattle is known to be a source for the microbial contamination of beef, with microorganisms transferred onto the carcass from the hide, during the slaughter and dressing processes. To assess the potential risk of carcass contamination from food-borne bacterial pathogens on cattle hides, a study was carried out involving 90 beef cattle in the South-West of England to determine the prevalence of these microorganisms. A one-pass swab technique was carried out to sample a measured area on the rump, flank and brisket of each animal. These swabs were processed in the laboratory to determine the prevalence of E. coli O157, Salmonella spp., and Campylobacter spp. on these hide areas. The most contaminated area was the brisket with one in five animals testing positive for E. coli O157 (22.2% prevalence on average) and approximately one in 10 animals testing positive for Salmonella spp. (10.0% prevalence on average). The least contaminated area on the cattle hides was the rump area (3.3% prevalence for E. coli O157, 2.2% prevalence for Salmonella spp.). Campylobacter spp. was not isolated from any samples taken from the 90 cattle studied. The results of this study indicate that the brisket area on the hide of cattle most frequently carries food-borne pathogens and is therefore most likely to lead to cross-contamination of beef during the de-hiding process. [Copyright &y& Elsevier]

Ten beef cattle feeding on silage were orally administered a marker organism (nalidixic acid resistant Escherichia coli K12) daily over six days. Subsequently, the administration of the marker organism was stopped, and the animals were divided into two groups (five animals each). The feed was removed from one group (i.e. fasted group) for 48 h, while the feeding of the control group was continued during that period, until both groups were subsequently slaughtered. During this pre-slaughter period, faecal shedding of total E. coli and E. coli K12, as well as of background flora (total aerobes, total anaerobes, and lactobacilli), was monitored in faecal material obtained by rectal swabs from each animal. After both 24 and 48 h of fasting, the levels of total E. coli shed significantly increased (P<0.01) in the fasted group compared with the control group; total anaerobes shed also increased (after 48 h fasting; P<0.05); while shedding of total aerobes and total lactobacilli did not change significantly. After slaughter of animals, the pH values and the levels of bacterial groups mentioned above were examined in contents of different sections of the gastrointestinal (GI) tract (rumen, abomasum, caecum, small intestine, colon). The pH values were significantly increased in rumen and decreased in abomasum (P<0.05) of the fasted animals compared with controls, but did not differ significantly in other GI sections. Significant decreases of total E. coli population (P<0.05) in abomasums and lactobacilli (P<0.01) in small intestines were observed in fasted animals, while other bacterial groups in other GI sections did not change significantly compared with controls. The marker organism E. coli K12 was not sufficiently competitive within the bovine GI tracts as it was pre-slaughter shed by, and post-slaughter isolated from, only a minority of animals regardless of the group. Overall, the results indicate that key fasting-induced changes of enteric E. coli populations, and influencing its faecal shedding, could have occurred within the relatively short caudal colon–rectum–anus region of the bovine GI tract. [Copyright &y& Elsevier]

Aims: To determine the prevalence and characteristics of verotoxigenic Escherichia coli (VTEC), enteropathogenic E. coli (EPEC) and necrotoxigenic E. coli (NTEC) in healthy cattle. Methods and Results: Faecal samples from 412 healthy cattle were screened for the presence of VTEC, EPEC and NTEC. Four isolates from each sample were studied. VTEC, EPEC and NTEC were isolated in 8.7%, 8.2% and 9.9% of the animals, respectively. VTEC and NTEC were isolated more frequently from calves and heifers than from adults. Seventy (4.2%), 69 (4.2%) and 74 (4.5%) of the 1648 E. coli isolates were VTEC, EPEC and NTEC, respectively. Seventeen (24.3%) of the VTEC strains were eae-positive. Thirty-six (51.4%) of VTEC strains belonged to E. coli serogroups associated with haemorrhagic colitis and haemolytic uraemic syndrome in humans. The serogroups most prevalent among the EPEC strains were O10, O26, O71, O145 and O156. Conclusions: Healthy cattle are a reservoir of VTEC, EPEC and NTEC. Significance and Impact of the Study: Although most of the VTEC strains were eae-negative, a high percentage of VTEC strains belonged to serogroups associated with severe disease in humans. [ABSTRACT FROM AUTHOR]

Examines the role of cattle water troughs as environmental reservoirs of Escherichia coli O157:H7. Ability to infect cattle after phenotypic, metabolic and genetic changes; Effect of water chlorination on survival of coliform in previously contaminated water troughs; Temporal pattern of fecal excretion of coliform.

Evaluates the virulence of Salmonella typhimurium 4/74 harboring mutations in htrA and purE in cattle. Susceptibility of cattle to oral or subcutaneous challenge with S. typhimurium 4/74; Measurement of interferon and antibodies to lipopolysaccharides in the sera of calves challenged with S. typhimurium 4/74.

The aims of the present study were to investigate the excretion of Eimeria alabamensis oocysts by young cattle during their first grazing season and during the first 16 days of their second grazing period. In trial 1, nine first-season grazing heifers were studied and found to have become infected with E. alabamensis shortly after turnout. The next grazing period they were turned out on to a permanent pasture together with two first-season grazing calves. Faecal samples were collected before turnout and then daily from day 3 to day 16. The second-season grazing heifers excreted insignificant numbers of E. alabamensis oocysts, whereas one of the two first-season grazing calves excreted up to 703 000 oocysts/g of faeces (OPG), indicating that the pasture was contaminated. In trial 2, faecal samples were collected from 12 calves before their first turnout in May, daily from day 2 to day 20 after turnout and then once a week until the end of September. The calves grazed pastures used in previous years by first-season grazing calves. Nine of the calves developed clinical E. alabamensis coccidiosis 4–7 days after turnout and excreted more than 950 000 OPG on days 9–10. By day 17 the oocyst excretion had decreased below 900 OPG and remained low throughout the rest of the grazing season. The results of the two studies indicate that reinfections with E. alabamensis are of little clinical importance in calves grazing contaminated pastures, and that young stock infected with E. alabamensis during their first grazing season may be used to cleanse contaminated pastures without risk of developing clinical coccidiosis. [ABSTRACT FROM AUTHOR]

Antimicrobials have been widely used in dairy farms to prevent and control dairy cattle diseases since 1960s. This led to the emergence of antimicrobial resistant bacteria (ARB) that, along with their antimicrobial resistance genes (ARGs), can spread from dairy farms to humans. Therefore, regular antimicrobial resistance (AMR) monitoring is important to implement proper mitigation measures. The objective of this study was to determine the prevalence of AMR and extended-spectrum beta-lactamases (ESBLs)-producing Escherichia coli in dairy cattle. A cross-sectional study was conducted in four dairy cattle farms (A-D) in East Tennessee. A total of 80 samples consisting of 20 samples each of bulk tank milk, feces, dairy cattle manure-amended soil, and prairie soil adjacent to the farms were collected and cultured for the isolation of E. coli . Tetracycline (TET r )-, third-generation cephalosporin (TGC r )- and nalidixic acid (NAL r )-resistant E. coli ( n  = 88) were isolated and identified on agar media supplemented with TET, cefotaxime, and NAL, respectively. TGC r E. coli were tested for ESBLs and other coselected ARGs. TET r (74%, n  = 88) was the most common, followed by TGC r (20%) and NAL r (8%). Farms had significant ( p  < 0.001) differences: the highest prevalence of TGC r (55%) and TET r (100%) were observed in farm D, while all NAL r isolates were from farm C. Over 83% of TGC r isolates ( n  = 18) harbored ESBL gene bla CTX-M . Majority (78%) of the E. coli isolates were multidrug-resistant (MDR), being positive for beta-lactams ( bla CTX-M ), TETs tet ( A ), tet ( B ), tet ( M )), sulfonamides ( sul 2), aminoglycosides ( strA ), and phenicols ( floR ). This study indicated the widespread occurrence of MDR ESBLs- E. coli in dairy cattle farms. AMR surveillance of more dairy farms and identification of farm-level risk factors are important to mitigate the occurrence and spread of ARB of significant public health importance, such as ESBLs- E. coli .

The increasing number of diversified small-scale farms (DSSF) that raise outdoor-based livestock in the USA reflects growing consumer demand for sustainably produced food. Diversified farms are small scale and raise a combination of multiple livestock species and numerous produce varieties. This 2015-2016 cross-sectional study aimed to describe the unique characteristics of DSSF in California, estimate the prevalence of Shiga toxin-producing Escherichia coli (STEC) in livestock and evaluate the association between risk factors and the presence of STEC in livestock, using generalised linear mixed models. STEC prevalence was 13.62% (76/558). Significant variables in the mixed-effect logistic regression model included daily maximum temperature (OR 0.95; CI 95% 0.91-0.98), livestock sample source (cattle (OR 4.61; CI 95% 1.64-12.96) and sheep (OR 5.29; CI 95% 1.80-15.51)), multiple species sharing the same barn (OR 6.23; CI 95% 1.84-21.15) and livestock having contact with wild areas (OR 3.63; CI 95% 1.37-9.62). Identification of STEC serogroups of public health concern (e.g. O157:H7, O26, O103) in this study indicated the need for mitigation strategies to ensure food safety by evaluating risk factors and management practices that contribute to the spread and prevalence of foodborne pathogens in a pre-harvest environment on DSSF.

Background: Anthrax is a disease that affects humans and animals. In Ethiopia, anthrax is a reportable disease and assumed to be endemic, although laboratory confirmation has not been routinely performed until recently. We describe the findings from the investigation of two outbreaks in Amhara region., Methods: Following reports of suspected outbreaks in Wag Hamra zone (Outbreak 1) and South Gondar zone (Outbreak 2), multi-sectoral teams involving both animal and public health officials were deployed to investigate and establish control programs. A suspect case was defined as: sudden death with rapid bloating or bleeding from orifice(s) with unclotted blood (animals); and signs compatible with cutaneous, ingestion, or inhalation anthrax ≤7 days after exposure to a suspect animal (humans). Suspect human cases were interviewed using a standard questionnaire. Samples were collected from humans with suspected anthrax (Outbreak 1 and Outbreak 2) as well as dried meat of suspect animal cases (Outbreak 2). A case was confirmed if a positive test was returned using real-time polymerase chain reaction (qPCR)., Results: In Outbreak 1, a total of 49 cows died due to suspected anthrax and 22 humans developed symptoms consistent with cutaneous anthrax (40% attack rate), two of whom died due to suspected ingestion anthrax. Three people were confirmed to have anthrax by qPCR. In Outbreak 2, anthrax was suspected to have caused the deaths of two livestock animals and one human. Subsequent investigation revealed 18 suspected cases of cutaneous anthrax in humans (27% attack rate). None of the 12 human samples collected tested positive, however, a swab taken from the dried meat of one animal case (goat) was positive by qPCR., Conclusion: We report the first qPCR-confirmed outbreaks of anthrax in Ethiopia. Both outbreaks were controlled through active case finding, carcass management, ring vaccination of livestock, training of health professionals and outreach with livestock owners. Human and animal health authorities should work together using a One Health approach to improve case reporting and vaccine coverage., Competing Interests: The authors have declared that no competing interests exist.

Three Gram-negative, rod-shaped, oxidase-positive, non-spore-forming, non-motile strains (C130915&#95;07 T , C150915&#95;16 and C150915&#95;17) were isolated from lymph nodes of Algerian cows. On the basis of 16S rRNA gene and whole genome similarities, the isolates were almost identical and clearly grouped in the genus Pseudochrobactrum . This allocation was confirmed by the analysis of fatty acids (C 19:cyclo , C 18 : 1 , C 18 : 0 , C 16 : 1 and C 16 : 0 ) and of polar lipids (major components: phosphatidylethanolamine, ornithine-lipids, phosphatidylglycerol, cardiolipin and phosphatidylcholine, plus moderate amounts of phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine and other aminolipids). Genomic, physiological and biochemical data differentiated these isolates from previously described Pseudochrobactrum species in DNA relatedness, carbon assimilation pattern and growth temperature range. Thus, these organisms represent a novel species of the genus Pseudochrobactrum , for which the name Pseudochrobactrum algeriensis sp. nov. is proposed (type strain C130915&#95;07 T =CECT30232 T =LMG 32378 T ).

Gram-positive coccoid bacteria were isolated from the nasal cavities of pigs and calves as well as from axillar and inguinal skin regions of pigs. Phylogenetic analysis of seven strains based on complete genome, 16S rRNA, hsp60 , dnaJ , rpoB and sodA gene sequences and MALDI-TOF MS profiles revealed that they belonged to the genus Macrococcus with the closest relatedness to Macrococcus canis , Macrococcus caseolyticus subsp. caseolyticus and Macrococcus caseolyticus subsp. hominis . DNA relatedness of the type strain JEK37 T with the type strains of M. canis , M. caseolyticus subsp. caseolyticus and M. caseolyticus subsp. hominis was 23.4, 23.1 and 23.0 % by digital DNA-DNA hybridization and 80.39, 80.45 and 80.87 % by average nucleotide identity (ANI) calculations, confirming that they do not belong to the same species. The DNA G+C content of JEK37 T was 35.65 mol%. The novel strains can be differentiated from M. canis KM 45013 T by the ability to fermentate d-ribose and by the absence of DNAase production and haemolysis, from M. caseolyticus subsp. caseolyticus CCUG 15606 T by the ability to fermentate sucrose and from both species by the inability to grow in 9 and 12% NaCl. They differ from M. caseolyiticus subsp. hominis by the presence of α-glucosidase. The most common fatty acids of JEK37 T were C 14 : 0 , C 18 : 1  ω9 c and C 18 : 0 . Known polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, aminolipid, aminoglycolipid, aminophospholipid, glycolipid and phospholipid. Cell-wall peptidoglycan of JEK37 T was of type A3α l-Lys-Gly 2 -L-Ser-Gly (similar to A11.3) and the respiratory quinolone was menaquinone 6. Based on their genotypic and chemotaxonomic characteristics, these strains represent a novel species of the genus Macrococcus , for which we propose the name Macrococcus armenti sp. nov. The type strain is JEK37 T (=DSM 112712 T =CCOS 1982 T ).

Common bacterial causes of bovine respiratory disease (BRD) include Histophilus somni , Mannheimia haemolytica , and Pasteurella multocida . Within M. haemolytica , two major genotypes are commonly found in cattle (1 and 2); however, genotype 2 strains are isolated from diseased lungs much more frequently than genotype 1 strains. Outer membrane proteins (OMPs) of H. somni , P. multocida , and genotype 2 M. haemolytica may be important factors for acquired host immunity. The predicted OMP differences between genotypes 1 and 2 M. haemolytica have been previously identified. In this study, we expanded the focus to include bovine-isolated strain genomes representing all three species and the two M. haemolytica genotypes. Reported here are the core genomes unique to each of them, core genomes shared between some or all combinations of the three species and two M. haemolytica genotypes, and predicted OMPs within these core genomes. The OMPs identified in this study are potential candidates for further studies and the development of interventions against BRD.

We compared antimicrobial resistance patterns of Salmonella enterica serovar Typhimurium (ST) of isolates from humans (n = 715) and cattle (n = 378) in the Pacific Northwest from 1982 through 1997. The major changes in antimicrobial resistance can be attributed to the widespread clonal dissemination of multidrug-resistant definitive phage type 104 ST. [ABSTRACT FROM AUTHOR]

Investigates the glucose transport by mixed ruminal bacteria from a cow. Transport systems; Dominance of the high-affinity, low velocity transport system in the feeding condition; Non-involvement of the proton motive force in the transport system; Phosphoenolpyruvate-dependent phosphotransferase system as the main system; Inhibition of the high-affinity system by sucrose, mannose and fructose.

Assesses the impact of rapid chilling and freeze-thaw of pre-rigor bovine muscle on the extractability and gelation properties of myofibrillar proteins. Relationships between gel strength and certain physical/biochemical changes occurring during postmortem storage; Thaw and muscle shortening measurement; PH measurement; Myofibrils and salt-soluble protein (SSP); More.

To investigate the presence of Coxiella burnetii in sheep and cattle, the two major ruminant populations of New Zealand, its seroprevalence was determined in aborting cattle and sheepdogs. These groups of animals were chosen because of their accessibility and the fact that they would be good indicators for the presence of the organism. A total of 2181 bovine and 12,556 canine samples were all seronegative. On the basis of these results and previous reports it is argued that New Zealand is free of coxiellosis or Q fever. [ABSTRACT FROM AUTHOR]

Laminitis is the inflammation of the lamella, and it has caused great economic loss to the dairy industry and attracted wide attention around the world. In recent years, microbiota are considered to play a significant role in various diseases processes. Therefore, our study aimed to explore the characteristics of ruminal microbiota in laminitis cows. The serum of bovines with or without laminitis was collected to detect concentrations of lipopolysaccharide (LPS), lactic acid, and histamine, and ruminal fluid was collected for 16S rDNA sequence analysis. The results showed a significant increase in LPS and lactic acid levels in the laminitis group compared to the control group cows. In addition, a higher abundance of Candidatus Saccharimonas , Saccharofermentans , Erysipelotrichaceae UCG-009 genus, Acetobacter pasteurianus , Clostridium papyrosolvens , Ruminococcaceae bacterium AE2021 , Porphyromonas crevioricanis , Pseudomonas boreopolis , Pseudomonas psychrotolerans , Rothia nasimurium , and Rothia pickettii was detected in the rumen fluid of laminitis bovines. In conclusion, this article confirms that there are differences in rumen microbiota between healthy and laminitis bovines. The elevated abundance of bacteria that enrich acid-enhancing metabolites, as well as increase the concentration of lactic acid and LPS, could be harmful factors to bovines and increase the risk of laminitis.

The present study investigated the serum microscopic agglutination test (MAT) among 203 bovine bulls with reproduction by natural means, without apparent signs of orchitis or inflammation of accessory reproductive glands. Simultaneously, the semen of all bulls was subjected to sperm viability analysis and PCR based on the 16S rRNA gene. PCR-positive results of semen samples were confirmed by sequencing. A modified seminal plasma agglutination (MSPA) test, replacing the blood serum of all bulls in the MAT with seminal plasma was performed as well. Eight (8/203 = 3.9%) semen samples from bulls were considered nonviable (necrospermia and azoospermia) without relation to the PCR diagnosis. No agglutinin titers were identified in MSPA test. A high frequency (132/203 = 65%) of leptospiral agglutinin titers was identified in the MAT, particularly for the Sejroe serogroup (Hardjo CTG, 100/203 = 49.3%; Wolffi 74/203 = 36.4%; Guaricura 72/203 = 35.5%; and Hardjoprajitno 56/203 = 27.6%). Three (3/203 = 1.5%) semen samples of bulls were positive in the PCR, but these results were not confirmed by sequencing. The high frequency of serovars from the Sejroe serogroup typically adapted to bovines indicates the need for measures for the prophylaxis/control of the pathogen on the sampled farms. Discrepancies among the MAT, sperm viability, and molecular detection of leptospires in semen highlight the need for a combination of methods to diagnose leptospirosis in bovine bulls. To our knowledge, modified seminal plasma agglutination is described for the first time here to investigate anti-Leptospira antibodies produced locally in the genital tract in the diagnosis of bovine leptospirosis among bulls that reproduce by natural means., (© 2021. Sociedade Brasileira de Microbiologia.)

Shiga toxigenic Escherichia coli (STEC) is one of the most important food-borne zoonotic bacterial pathogens responsible for causing gastrointestinal infections, haemorrhagic colitis and haemolytic uremic syndrome. The present study was aimed to isolate and characterize STEC from neonatal dairy calves, animal handlers and their surrounding environment and to establish the genetic relationship among isolates by multilocus sequence typing (MLST). A total number of 115 samples were collected and processed for the isolation of E. coli. The occurrence rate of E. coli was 92.2% (106/115), of which, 18 were typed as STEC. Antibacterial susceptibility analysis revealed 11 (61.1%) strains as multiple drug-resistant (MDR). MLST analysis has delineated 16 sequence types (STs) including nine novel STs. Among STs, ST58 dominated with three strains and was recovered from the environment and neonatal calves. Strains from neonatal calves and humans showed genetic relatedness with significant bootstrap support values indicative of zoonotic transmission potentiality. Analysis of 211 global isolates belonging to 61 STs indicated predominant STs (ST 21, ST 33 and ST 3416) that can be either host-specific (ST 33 and ST 3416) or can be shared among human and bovine hosts (ST 21). The MLST analysis indicates genetic relatedness among isolates and the results predispose inter-host transmission and zoonotic spread., (© 2021. Sociedade Brasileira de Microbiologia.)

Background: The effect of live yeast Saccharomyces cerevisiae strain CNCM I-1077 (SC) on the ruminal degradability of different forages commonly found in dairy diets in South America was evaluated. We also assessed if SC supplementation interacts with forage group to affect ruminal fiber degradability. Four non-lactating rumen-cannulated Holstein cows were randomly assigned to two treatment sequences: Control-SC-Control or SC-Control-SC, in a switchback design, with three 30-day periods. Cows in the SC treatment were supplied with 1 × 10 10 colony-forming units of yeast daily via rumen cannula. In situ degradability of dry matter (DM) and neutral detergent fiber (aNDF) was measured in 15 forages collected in South America. Forages were assigned to one of three groups: corn silages; tropical grasses (sugarcane silages and tropical grass silages); and temperate grasses and alfalfa (oat silages, ryegrass silages, alfalfa silage, and alfalfa hay)., Results: Cows supplemented with SC had higher (P = 0.05) counts of yeasts and lower (P = 0.03) concentration of lactate in rumen fluid. There was no interaction between forage group and yeast supplementation (P > 0.10) on in situ degradability. The SC increased DM (by 4.6%) and aNDF degradation (by 10.3%) at 24 h of incubation (P < 0.05). Metabolomics revealed that a chemical entity (C 17 H 29 N 6 O 3 , m/z 365.2284 [M + H] + ) from the family of lipids and related molecules was suppressed in the rumen fluid of cows supplemented with SC., Conclusion: The SC supplementation improved DM and aNDF degradability regardless of the forage group. © 2021 Society of Chemical Industry., (© 2021 Society of Chemical Industry.)

Intestinal carriage of extended spectrum β-lactamase (ESBL)-producing Escherichia coli is a frequent, increasing, and worrying phenomenon, but little is known about the molecular scenario and the evolutionary forces at play. We screened 45 veal calves, known to have high prevalence of carriage, for ESBL-producing E. coli on 514 rectal swabs (one randomly selected colony per sample) collected over 6 months. We characterized the bacterial clones and plasmids carrying bla ESBL genes with a combination of genotyping methods, whole genome sequencing, and conjugation assays. One hundred and seventy-three ESBL-producing E. coli isolates [ bla CTX-M-1 (64.7%), bla CTX-M-14 (33.5%), or bla CTX-M-15 (1.8%)] were detected, belonging to 32 bacterial clones, mostly of phylogroup A. Calves were colonized successively by different clones with a trend in decreasing carriage. The persistence of a clone in a farm was significantly associated with the number of calves colonized. Despite a high diversity of E. coli clones and bla CTX-M -carrying plasmids, few bla CTX-M gene/plasmid/chromosomal background combinations dominated, due to (i) efficient colonization of bacterial clones and/or (ii) successful plasmid spread in various bacterial clones. The scenario "clone versus plasmid spread" depended on the farm. Thus, epistatic interactions between resistance genes, plasmids, and bacterial clones contribute to optimize fitness in specific environments. IMPORTANCE The gut microbiota is the epicenter of the emergence of resistance. Considerable amount of knowledge on the molecular mechanisms of resistance has been accumulated, but the ecological and evolutionary forces at play in nature are less studied. In this context, we performed a field work on temporal intestinal carriage of extended spectrum β-lactamase (ESBL)-producing Escherichia coli in veal farms. Veal calves are animals with one of the highest levels of ESBL producing E. coli fecal carriage, due to early high antibiotic exposure. We were able to show that calves were colonized successively by different ESBL-producing E. coli clones, and that two main scenarios were at play in the spread of bla CTX-M genes among calves: efficient colonization of several calves by a few bacterial clones and successful plasmid spread in various bacterial clones. Such knowledge should help develop new strategies to fight the emergence of antibiotic-resistance.

Bovine brucellosis induces abortion in cows, produces important economic losses, and causes a widely distributed zoonosis. Its eradication was achieved in several countries after sustained vaccination with the live attenuated Brucella abortus S19 vaccine, in combination with the slaughtering of serologically positive animals. S19 induces antibodies against the smooth lipopolysaccharide (S-LPS), making difficult the differentiation of infected from vaccinated bovines. We developed an S19 strain constitutively expressing the green fluorescent protein (S19-GFP) coded in chromosome II. The S19-GFP displays similar biological characteristics and immunogenic and protective efficacies in mice to the parental S19 strain. S19-GFP can be distinguished from S19 and B. abortus field strains by fluorescence and multiplex PCR. Twenty-five heifers were vaccinated withS19-GFP (5×109 CFU) by the subcutaneous or conjunctival routes and some boosted with GFP seven weeks thereafter. Immunized animals were followed up for over three years and tested for anti-S-LPS antibodies by both the Rose Bengal test and a competitive ELISA. Anti-GFP antibodies were detected by an indirect ELISA and Western blotting. In most cases, anti-S-LPS antibodies preceded for several weeks those against GFP. The anti-GFP antibody response was higher in the GFP boosted than in the non-boosted animals. In all cases, the anti-GFP antibodies persisted longer, or at least as long, as those against S-LPS. The drawbacks and potential advantages of using the S19-GFP vaccine for identifying vaccinated animals in infected environments are discussed., Competing Interests: The authors have declared that no competing interests exist.

Four yeast isolates with an affinity to the genus Wickerhamiella were obtained from beach sand, a marine zoanthid and a tree exudate at different localities in Brazil. Two other isolates with almost identical ITS and D1/D2 sequences of the large subunit rRNA gene were isolated from the small intestine of cattle and a grease trap in Thailand. These isolates represent a novel species phylogenetically related to Wickerhamiella verensis , Wickerhamiella osmotolerans , Wickerhamiella tropicalis , Wickerhamiella sorbophila and Wickerhamiella infanticola . The novel species differs by 15-30 nucleotide differences from these species in the D1/D2 sequences. The name Wickerhamiella martinezcruziae f.a., sp. nov. is proposed. The holotype of Wickerhamiella martinezcruziae sp. nov. is CBS 16104 T . The MycoBank number is MB 839328.

A novel growth-promoting and indole acetic acid-producing strain, designated NEAU-LLB T , was isolated from cow dung collected from Shangzhi, Heilongjiang Province, PR China. Cells of strain NEAU-LLB T were Gram-stain-positive, non-motile, aerobic and non-spore-forming. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain NEAU-LLB T belonged to the genus Microbacterium . Strain NEAU-LLB T had high 16S rRNA sequence similarities of 98.81 and 98.41 % to Microbacterium paludicola DSM 16915 T and Microbacterium marinilacus DSM 18904 T , and less than 98 % to other members of the genus Microbacterium . Chemotaxonomic characteristics showed that MK-11 and MK-12 were detected as the predominant menaquinones. The peptidoglycan contained glutamic acid, aspartic acid, glycine, ornithine and a small amount of alanine, with ornithine as the diagnostic diamino acid. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid. The major fatty acids were identified as anteiso-C 15 : 0 , iso-C 16 : 0 and iso-C 17 : 0 . The genomic DNA G+C content of strain NEAU-LLB T was 70.2 mol%. In addition, the average nucleotide identity values between strain NEAU-LLB T and its reference strains, M. paludicola DSM 16915 T , M. marinilacus DSM 18904 T and M. album SYSU D8007 T , were found to be 81.1, 79.4 and 78.7 %, respectively, and the level of digital DNA-DNA hybridization between them were 23.8, 22.6 and 21.8 %, respectively. Based on the phenotypic, phylogenetic and genotypic data, strain NEAU-LLB T is considered to represent a novel species of the genus Microbacterium , for which the name Microbacterium stercoris sp. nov is proposed, with NEAU-LLB T (=CCTCC AA 2018028 T =JCM 32660 T ) as the type strain.

A Gram-stain-negative, non-spore-forming, yellow-pigmented, aerobic, pleomorphic rod-shaped bacterium, designated ZY171143 T , was isolated from faeces of a cow with diarrhoea in Wenshan, Yunnan Province, south-west China and its taxonomic position was studied. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain ZY171143 T belonged to the family Weeksellaceae and was most closely related to the only species of the genus Faecalibacter , Faecalibacter macacae CCTCC AB 2016016 T with a sequence similarity of 97.8 %. The genomic OrthoANI and digital DNA-DNA hybridization values between the strain and F. macacae CCTCC AB 2016016 T were 86.2 and 30.5 %, respectively. The genomic G+C content was 31.1 mol%. The predominant fatty acids (>5 %) were C 15 : 0 iso, C 17 : 0 iso 3OH, C 16 : 0 , C 16 : 1  ω5 c and summed feature 3 (C 16 : 1  ω7 c and/or 16 : 1 ω6c). The major polar lipids were phosphatidylethanolamine, triacylglycerol and sulfonolipid. The sole respiratory quinone was MK-6. These chemotaxonomic characterizations also revealed that strain ZY171143 T was a member of the genus Faecalibacter . Based on the phenotypic, chemotaxonomic and genotypic data, strain ZY171143 T represents a novel species within the genus Faecalibacter , for which the name Faecalibacter bovis sp. nov. is proposed. The type strain is ZY171143 T (=CGMCC 1.13663 T =KCTC 62642 T ).

A novel Gram-stain negative, aerobic, halotolerant, motile, rod-shaped, predatory bacterium ASxL5 T , was isolated from a bovine slurry tank in Nottinghamshire, UK using Campylobacter hyointestinalis as prey. Other Campylobacter species and members of the Enterobacteriaceae were subsequently found to serve as prey. Weak axenic growth on Brain Heart Infusion agar was achieved upon subculture without host cells. The optimal growth conditions were 37 °C, at pH 7. Transmission electron microscopy revealed some highly unusual morphological characteristics related to prey availability. Phylogenetic analyses using 16S rRNA gene sequences showed that the isolate was related to members of the Oceanospirillaceae family but could not be classified clearly as a member of any known genus. Whole genome sequencing of ASxL5 T confirmed the relationship to members the Oceanospirillaceae. Database searches revealed that several ASxL5 T share 16S rRNA gene sequences with several uncultured bacteria from marine, and terrestrial surface and subsurface water. We propose that strain ASxL5 T represents a novel species in a new genus. We propose the name Venatorbacter cucullus gen. nov., sp. nov. with ASxL5 T as the type strain., (© 2021. The Author(s).)

The number of bacterial genomes deposited each year in public databases is growing exponentially. However, efforts to use these genomes to track trends in antimicrobial resistance (AMR) have been limited thus far. We used 22,102 genomes from public databases to track AMR trends in nontyphoidal Salmonella in food animals in the United States. In 2018, genomes deposited in public databases carried genes conferring resistance, on average, to 2.08 antimicrobial classes in poultry, 1.74 in bovines, and 1.28 in swine. This represents a decline in AMR of over 70% compared to the levels in 2000 in bovines and swine, and an increase of 13% for poultry. Trends in resistance inferred from genomic data showed good agreement with U.S. phenotypic surveillance data (weighted mean absolute difference ± standard deviation, 5.86% ± 8.11%). In 2018, resistance to 3rd-generation cephalosporins in bovines, swine, and poultry decreased to 9.97% on average, whereas in quinolones and 4th-generation cephalosporins, resistance increased to 12.53% and 3.87%, respectively. This was concomitant with a decrease of bla CMY-2 but an increase in bla CTX-M-65 and gyrA D87Y (encoding a change of D to Y at position 87). Core genome single-nucleotide polymorphism (SNP) phylogenies show that resistance to these antimicrobial classes was predominantly associated with Salmonella enterica serovar Infantis and, to a lesser extent, S. enterica serovar Typhimurium and its monophasic variant I 4,[5],12:i:-, whereas quinolone resistance was also associated with S. enterica serovar Dublin. Between 2000 and 2018, trends in serovar prevalence showed a composition shift where S. Typhimurium decreased while S. Infantis increased. Our findings illustrate the growing potential of using genomes in public databases to track AMR in regions where sequencing capacities are currently expanding. IMPORTANCE Next-generation sequencing has led to an exponential increase in the number of genomes deposited in public repositories. This growing volume of information presents opportunities to track the prevalence of genes conferring antimicrobial resistance (AMR), a growing threat to the health of humans and animals. Using 22,102 public genomes, we estimated that the prevalence of multidrug resistance (MDR) in the United States decreased in nontyphoidal Salmonella isolates recovered from bovines and swine between 2000 and 2018, whereas it increased in poultry. These trends are consistent with those detected by national surveillance systems that monitor resistance using phenotypic testing. However, using genomes, we identified that genes conferring resistance to critically important antimicrobials were associated with specific MDR serovars that could be the focus for future interventions. Our analysis illustrates the growing potential of public repositories to monitor AMR trends and shows that similar efforts could soon be carried out in other regions where genomic surveillance is increasing.

The use of phenicol antibiotics in animals has increased. In recent years, it has been reported that the transferable gene mediates phenicol-oxazolidinone resistance. This study analyzed the prevalence and characteristics of phenicol-oxazolidinone resistance genes in Enterococcus faecalis and Enterococcus faecium isolated from food-producing animals and meat in Korea in 2018. Furthermore, for the first time, we reported the genome sequence of E. faecalis strain, which possesses the phenicol-oxazolidinone resistance gene on both the chromosome and plasmid. Among the 327 isolates, optrA , poxtA , and fexA genes were found in 15 (4.6%), 8 (2.5%), and 17 isolates (5.2%), respectively. Twenty E. faecalis strains carrying resistance genes belonged to eight sequence types (STs), and transferability was found in 17 isolates. The genome sequences revealed that resistant genes were present in the chromosome or plasmid, or both. In strains EFS17 and EFS108, optrA was located downstream of the ermA and ant ( 9 ) -1 genes. The strains EFS36 and EFS108 harboring poxtA -encoding plasmid cocarried fexA and cfr ( D ). These islands also contained IS1216E or the transposon Tn554, enabling the horizontal transfer of the phenicol-oxazolidinone resistance with other antimicrobial-resistant genes. Our results suggest that it is necessary to promote the prudent use of antibiotics through continuous monitoring and reevaluation.

Background: The Shiga toxin-producing Escherichia coli (STEC) represented a great risk to public health. In this study, 60 STEC strains recovered from broiler and duck fecal samples, cow's milk, cattle beef, human urine, and ear discharge were screened for 12 virulence genes, phenotypic and genotypic antimicrobial resistance, and multiple-locus variable-number tandem-repeat analysis (MLVA)., Results: The majority of strains harbored Shiga toxin 1 (stx 1 ) and stx 1d , stx 2 and stx 2e , and ehxA genes, while a minority harbored stx 2c subtype and eaeA. We identified 10 stx gene combinations; most of strains 31/60 (51.7%) exhibited four copies of stx genes, namely the stx 1 , stx 1d , stx 2 , and stx 2e , and the strains exhibited a high range of multiple antimicrobial resistance indices. The resistance genes blaCTX-M-1 and blaTEM were detected. For the oxytetracycline resistance genes, most of strains contained tetA, tetB, tetE, and tetG while the tetC was present at low frequency. MLVA genotyping resolved 26 unique genotypes; genotype 21 was highly prevalent. The six highly discriminatory loci DI = 0.9138 are suitable for the preliminary genotyping of STEC from animals and humans., Conclusions: The STEC isolated from animals are virulent, resistant to antimicrobials, and genetically diverse, thus demands greater attention for the potential risk to human., (© 2021. The Author(s).)

This study investigated the effect of moderate risk level (8 µg/kg) AFB 1 in diet supplemented with or without adsorbents on lactation performance, serum parameters, milk AFM 1 content of healthy lactating cows and the AFM 1 residue exposure risk in different human age groups. Forty late healthy lactating Holstein cows (270 ± 22 d in milk; daily milk yield 21 ± 3.1 kg/d) were randomly assigned to four treatments: control diet without AFB 1 and adsorbents (CON), CON with 8 μg/kg AFB 1 (dry matter basis, AF), AF + 15 g/d adsorbent 1 (AD1), AF + 15 g/d adsorbent 2 (AD2). The experiment lasted for 19 days, including an AFB 1 -challenge phase (day 1 to 14) and an AFB 1 -withdraw phase (day 15 to 19). Results showed that both AFB 1 and adsorbents treatments had no significant effects on the DMI, milk yield, 3.5% FCM yield, milk components and serum parameters. Compared with the AF, AD1 and AD2 had significantly lower milk AFM 1 concentrations (93 ng/L vs. 46 ng/L vs. 51 ng/L) and transfer rates of dietary AFB 1 into milk AFM 1 (1.16% vs. 0.57% vs. 0.63%) ( p < 0.05). Children aged 2-4 years old had the highest exposure risk to AFM 1 in milk in AF, with an EDI of 1.02 ng/kg bw/day and a HI of 5.11 (HI > 1 indicates a potential risk for liver cancer). Both AD1 and AD2 had obviously reductions in EDI and HI for all population groups, whereas, the EDI (≥0.25 ng/kg bw/day) and HI (≥1.23) of children aged 2-11 years old were still higher than the suggested tolerable daily intake (TDI) of 0.20 ng/kg bw/day and 1.00 (HI). In conclusion, moderate risk level AFB 1 in the diet of healthy lactating cows could cause a public health hazard and adding adsorbents in the dairy diet is an effective measure to remit AFM 1 residue in milk and its exposure risk for humans.

Group B Streptococcus (GBS) is a leading cause of human neonatal infections and bovine mastitis. We report here the unusual finding of the human-adapted hypervirulent serotype III/ST17 clone in a bovine GBS isolated in 1987 in Brazil. This isolate shared several phenotypic and genotypic characteristics with serotype III/ST17 strains obtained from human sources, including PFGE pattern, pilus genes, lactose fermentation, DNase activity, and antimicrobial susceptibility profile, highlighting the importance of continued tracking of GBS in the One Health scope. The study brings new evidence for the potential interspecies transmission and sheds new light into evolution aspects of the pathogen Group B Streptococcus (GBS) by reporting the occurrence of an ancient bovine GBS isolate belonging to a variant currently known to be exclusively found in human hosts., (© 2021. Sociedade Brasileira de Microbiologia.)

Background: Analysis and prediction of complex traits using microbiome data combined with host genomic information is a topic of utmost interest. However, numerous questions remain to be answered: how useful can the microbiome be for complex trait prediction? Are estimates of microbiability reliable? Can the underlying biological links between the host's genome, microbiome, and phenome be recovered?, Methods: Here, we address these issues by (i) developing a novel simulation strategy that uses real microbiome and genotype data as inputs, and (ii) using variance-component approaches (Bayesian Reproducing Kernel Hilbert Space (RKHS) and Bayesian variable selection methods (Bayes C)) to quantify the proportion of phenotypic variance explained by the genome and the microbiome. The proposed simulation approach can mimic genetic links between the microbiome and genotype data by a permutation procedure that retains the distributional properties of the data., Results: Using real genotype and rumen microbiota abundances from dairy cattle, simulation results suggest that microbiome data can significantly improve the accuracy of phenotype predictions, regardless of whether some microbiota abundances are under direct genetic control by the host or not. This improvement depends logically on the microbiome being stable over time. Overall, random-effects linear methods appear robust for variance components estimation, in spite of the typically highly leptokurtic distribution of microbiota abundances. The predictive performance of Bayes C was higher but more sensitive to the number of causative effects than RKHS. Accuracy with Bayes C depended, in part, on the number of microorganisms' taxa that influence the phenotype., Conclusions: While we conclude that, overall, genome-microbiome-links can be characterized using variance component estimates, we are less optimistic about the possibility of identifying the causative host genetic effects that affect microbiota abundances, which would require much larger sample sizes than are typically available for genome-microbiome-phenome studies. The R code to replicate the analyses is in https://github.com/miguelperezenciso/simubiome ., (© 2021. The Author(s).)

This study describes JE7A12 T (=ATCC TSD-225 T =NCTC 14479 T ), an isolate from the ruminal content of a dairy cow. Phenotypic and genotypic traits of the isolate were explored. JE7A12 T was found to be a strictly anaerobic, catalase-negative, oxidase-negative, coccoid bacterium that grows in chains. The API 50 CH carbon source assay detected fermentation of d-glucose, d-fructose, d-galactose, glycogen and starch. HPLC showed acetate to be the major fermentation product as a result of carbohydrate fermentation. Phylogenetic analysis of JE7A12 T based on 16S rRNA nucleotide sequence and amino acid sequences from the whole genome indicated a divergent lineage from the closest neighbours in the genus Ruminococcus . The results of 16S rRNA sequence comparison, whole genome average nucleotide identity (ANI) and DNA G+C content data indicate that JE7A12 T represents a novel species which we propose the name Ruminococcus bovis with JE7A12 T as the type strain.

Drug resistance has been partly driven by the overuse of antimicrobials in agricultural animal feed. Better understanding of antibiotic resistance in bovine gut is needed to assess its potential effects based on metagenomic approach and analysis. In this study, we collected 40 fecal samples to explore drug resistance derived from antibiotic use in the bacterial community by an analysis of the diversities and differences of antibiotic-resistant genes (ARGs) in the gut microbiota from yak, beef, and dairy cattle. Overall, 1688 genes were annotated, including 734 ARG subtypes. The ARGs were related to tetracyclines, quinolones, β-lactam, and aminoglycosides, in accordance with the antibiotics widely used in the clinic for humans or animals. The emergence, prevalence, and differences in resistance genes in the intestines of yaks, beef, and dairy cattle may be caused by the selective pressure of different feeding patterns, where yaks were raised without antibiotics for growth promotion. In addition, the abundance of ARGs in yak was lower than in beef and dairy cattle, whereas the abundance of integron, a kind of mobile genetic elements (MGEs) was higher in yaks than those in beef and dairy cattle. Furthermore, the results of this study could provide the basis for a comprehensive profile of various ARGs among yak, beef, and dairy cattle in future., (© 2021. The Author(s).)

Subacute rumen acidosis (SARA) occurs when highly fermentable carbohydrates are introduced into the diet, decreasing pH and disturbing the microbial ecology of the rumen. Rumen amylolytic bacteria rapidly catabolize starch, fermentation acids accumulate in the rumen and reduce environmental pH. Historically, antibiotics (e.g., monensin, MON) have been used in the prevention and treatment of SARA. Biochanin A (BCA), an isoflavone produced by red clover (Trifolium pratense), mitigates changes associated with starch fermentation ex vivo. The objective of the study was to determine the effect of BCA on amylolytic bacteria and rumen pH during a SARA challenge. Twelve rumen fistulated steers were assigned to 1 of 4 treatments: HF CON (high fiber control), SARA CON, MON (200 mg d-1), or BCA (6 g d-1). The basal diet consisted of corn silage and dried distiller's grains ad libitum. The study consisted of a 2-wk adaptation, a 1-wk HF period, and an 8-d SARA challenge (d 1-4: 40% corn; d 5-8: 70% cracked corn). Samples for pH and enumeration were taken on the last day of each period (4 h). Amylolytic, cellulolytic, and amino acid/peptide-fermenting bacteria (APB) were enumerated. Enumeration data were normalized by log transformation and data were analyzed by repeated measures ANOVA using the MIXED procedure of SAS. The SARA challenge increased total amylolytics and APB, but decreased pH, cellulolytics, and in situ DMD of hay (P < 0.05). BCA treatment counteracted the pH, microbiological, and fermentative changes associated with SARA challenge (P < 0.05). Similar results were also observed with MON (P < 0.05). These results indicate that BCA may be an effective alternative to antibiotics for mitigating SARA in cattle production systems., Competing Interests: The authors have declared that no competing interests exist.

Enterobacteria that produce extended-spectrum β-lactamase (ESBL) such as Escherichia coli (E. coli) are common in our environment and known to cause serious health implications in humans and animals. β-lactam antibiotics such as penicillins, cephalosporins and monobactams are the most commonly used anti-bacterials in both humans and animals, however, Gram negative bacteria (such as E. coli) that produces extended-spectrum β-lactamases (ESBLs) have the ability to hydrolyze most β-lactams therefore making them resistant to β-lactam antibiotics. Recent extensive researches on the epidemiology and genetic characteristics of extended-spectrum β-lactamase (ESBL)-producing E. coli reported the existence of ESBL-producing E. coli in humans, companion animals and poultry. Therefore, this experiment was performed to investigate the prevalence and genetic characteristics of β-lactamase producing E. coli isolated from beef cattle farms in the Sichuan-Chongqing circle of China. Phenotypic confirmation of ESBL-producing E. coli was performed using the double disk synergy test. Polymerase Chain Reaction (PCR) was used to detect bla CTX-M , bla SHV and bla TEM gene codes, then after, isolates were divided into different phylogenetic groups and multi-locus sequence typing (MLST). The results showed that out of the 222 E. coli strains isolated from the beef cattle, 102 strains showed ESBL phenotypes. The PCR results showed that bla CTX-M was the predominant ESBL gene identified among the E. coli strains with 21 (9.5%) isolates having this gene, followed by bla SHV which was found in 18 (8.1%) isolates. The majority of these ESBL positive isolates were assigned to phylogroup A (19.8%) followed by phylogroup B1 (13.5%). In addition, from the MLST results on ESBL positive isolates (n = 30) we identified 19 STs, ST398 (ST398cplx) and ST7130 which were the prevalent population (20%). In conclusion, the high prevalence of CTX-M, and SHV in the study confirmed its association with E. coli infection; therefore, this calls for health concerns on ESBL-producing E. coli. As far as we know, this is the first comprehensive research report relating to ESBL-producing E. coli incidence in Chinese beef cattle.

Campylobacter is one of the most common causes of foodborne bacterial infections worldwide. Why poultry has been shown to be one of the most significant sources of these bacteria, ruminants, especially cattle, are also responsible for a high number of human Campylobacter jejuni , and to a lesser extent Campylobacter coli , infections. In this study, bovine and pig carcasses in Poland were investigated for the presence of Campylobacter and for their antimicrobial resistance. A total of 204 swabs from bovine carcasses and 355 swab samples from pig carcasses were tested during 2014-2018. Campylobacter was identified in 129 (36.3%) of the pig and in 11 (5.4%) of the bovine carcasses, respectively. The pig isolates were classified as C. coli (121; 34.1%) or C. jejuni (8; 2.3%), whereas the bovine Campylobacter were identified either as C. jejuni (8; 3.9% isolates) or C. coli (3; 1.5% strains). Resistance of the isolates ( n  = 140) to erythromycin, ciprofloxacin, nalidixic acid, streptomycin, and tetracycline revealed that the vast majority of C. coli was resistant to streptomycin (106 isolates; 85.5%), tetracycline (97; 78.2%), nalidixic acid (90; 72.6%), and ciprofloxacin (88; 71.0%). Among C. jejuni isolates ( n  = 16) the resistance rates to all antibiotics were lower than in C. coli , irrespective of the origin. A total of 74 of 121 (61.2%) C. coli isolates from the pig carcasses and one of three such isolates from the bovine samples were multiresistant. Most of the C. coli (64 isolates; 85.3%) had the ciprofloxacin+nalidixic acid+streptomycin+tetracycline resistance profile. The results suggest that pig and bovine carcasses may be an underestimated reservoir of Campylobacter , especially for C. coli in pigs. The high antimicrobial resistance rates of such strains to streptomycin, quinolones, and tetracyclines highlight the need for monitoring of these bacteria in such food and food products.

Mastitis is the economically most important disease of dairy cows. This study used PacBio single-molecule real-time sequencing technology to sequence the full-length 16S rRNAs from 27 milk samples (18 from mastitis and nine from healthy cows; the cows were at different stages of lactation). We observed that healthy or late stage milk microbiota had significantly higher microbial diversity and richness. The community composition of the microbiota of different groups also varied greatly. The healthy cow milk microbiota was predominantly comprised of Lactococcus lactis , Acinetobacter johnsonii , and Bacteroides dorei , while the milk from mastitis cows was predominantly comprised of Bacillus cereus . The prevalence of L. lactis and B. cereus in the milk samples was confirmed by digital droplets PCR. Differences in the milk microbiota diversity and composition could suggest an important role for some these microbes in protecting the host from mastitis while others associated with mastitis. The results of our research serve as useful references for designing strategies to prevent and treat mastitis.

Multiple outbreaks of Mycoplasma bovis (M. bovis) have been reported in North American bison (Bison bison) in Alberta, Manitoba, Saskatchewan, Nebraska, New Mexico, Montana, North Dakota, and Kansas. M. bovis is mainly spread through direct contact and disseminated via animal movements thus, reliable genotyping is crucial for epidemiological investigations. The present study describes the genotyping of sixty-one M. bovis strains from cattle and bison isolated from different provinces of Canada by multi locus sequence typing (MLST), and multiple-locus variable-number tandem repeat analysis (MLVA). The sixty M. bovis clinical isolates together with the reference strain PG45 were divided into ten sequence types by MLST. Three novel sequence types were identified. Two isolates, one from cattle and one from bison shared the same sequence type, whereas one strain had the same sequence type as PG45. The cattle isolates could be further subdivided in Clade A with two subclades and bison isolates were grouped in Clade B with two subclades. With the exception of one animal, isolates originating from the same animal had the same sequence type. The sixty-one isolates also formed three main clades with several subclades when analyzed by MLVA. A total of 20 VNTR (Variable number tandem repeats) types were distinguished, 8 in cattle and 12 in bison isolates. The results showed multiple sequence types and genotype populations of M. bovis in bison and cattle. The results may further help to understand the evolution of M. bovis and develop strain specific or sequence type diagnostic tools., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The purpose of this study was to evaluate the role of bacterial and viral agents in cattle abortions from farms of the southern region of Minas Gerais State, through a retrospective and prospective study of abortion cases received by the Setor de Patologia, from the Universidade Federal de Lavras by histopathological, immunohistochemical and microbiological exams. Of the 30 fetuses with microscopic lesions, eight had lesions consistent with bacterial agents and three with viral agents. The etiologic agents diagnosed were Brucella sp, Leptospira sp, Staphylococcus sp and bovine herpesvirus. [ABSTRACT FROM AUTHOR]

In cattle, Ureaplasma diversum has been associated with decreased fertility, granular vulvovaginitis, endometritis, salpingitis and spontaneous abortion in cows and seminal vesiculitis, balanoposthitis and changes in bull sperm. The presence of U. diversum within the Australian cattle population has not been established. One of the aims of this study was to determine if U. diversum was present in Australian cattle, using culture and polymerase chain reaction ( PCR), both of which are considered to be gold standards for bacterial identification. Of 100 samples collected from 66 male and 34 female cattle, 15 were positive for U. diversum. Therefore, Australia can no longer be considered free of U. diversum. Further studies should be conducted to ascertain the effects of U. diversum within Australian cattle herds and, if warranted, to investigate prevention, treatment and eradication protocols. [ABSTRACT FROM AUTHOR]

Abstract: Shiga toxin-producing Escherichia coli (STEC) O157:H7 represents a major public health concern worldwide, with cattle recognized as their main natural reservoir. The aim of this work was to determine the prevalence and the pheno-genotypic characteristics of STEC O157:H7 in a herd with 268 cattle of the fighting bulls breed (De Lidia breed) managed under extensive conditions in the South-West of Spain. Rectal–anal swabs of all animals were collected and examined for STEC O157:H7 by performing an immunomagnetic concentration and separation procedure combined with PCR, and the resulting isolates were characterized by both phenotypic and genotypic methods. Overall, STEC O157:H7 was isolated from seven animals (2.6%) in the herd. The PCR procedure indicated that all seven isolates displayed stx 2, eae-γ1, ehxA, O157 rfbE, and fliCh7 genes. They belonged to phage types 4 (one isolate) and 42 (two isolates), and four isolates reacted with typing phages but did not conform to a recognized pattern. Among the seven isolates there were five indistinguishable PFGE patterns and other two which differed only in⩽2 restriction fragments, supporting the existence of horizontal transmission among animals in the herd. The present study demonstrates that cattle managed under extensive conditions in Spain can excrete STEC O157:H7 with their faeces. To our knowledge this is the first isolation of this pathogen from De Lidia cattle. [Copyright &y& Elsevier]

This study aimed to determine the role of Bartonella as an endocarditis agent in cattle. Bartonella bovis was identified by PCR, gene sequences analysis, and specific internal transcribed spacer amplicon product size in 2 bovine endocarditis cases with high antibody titers, which demonstrates that B. bovis is a pathogen for cattle. [ABSTRACT FROM AUTHOR]

Background: The microbiome of the digestive tract of ruminants contains microbial ecosystem that is affected by both environmental and genetic factors. The subject of this study concerns the influence of selected genetic factors, such as species of animals and "host" individual differences on the digestive tract microbiome composition. The results show the core microbiological composition (Firmicutes and Bacteroidetes) of ruminants digestive tract (based on feces) depending on breed and "host". The Bacteroidetes and Firmicutes phyla are the most abundant in ruminants digestive tract. The aim of the study was to determine the differences prevalence level of Bacteroidetes and Firmicutes phyla in feces of Charolaise cattle and Polish Olkuska Sheep with respect to intra- and inter-species variability., Results: The research group in the experiment consisted of animals at the age of 3 months kept in the same environmental conditions - rams of Polish Olkuska Sheep (n = 10) and Charolaise bulls (n = 10). Feces were collected individually from each animal (animals without disease symptoms were selected), living on the same environmental conditions. The analysis of the results in terms of species showed differences in the Firmicutes phylum level and Lactobacillaceae family between rams and bulls. Subsequently, the analysis performed for the "host effect" showed differentiation in the levels of the Bacteroidetes and Firmicutes phyla between individuals in a group and also between the groups., Conclusion: The obtained results suggest that, apart from the diet and the environment, the species and the individual host are equally important factors influencing the microbiological composition of the digestive system of ruminants.

Clostridioides difficile causes severe colitis in people and is a significant enteric pathogen in many species of animals, including swine, horses, and potentially cattle. C. difficile is shed in feces, and transmission occurs horizontally via the fecal-oral route. Livestock has been suggested as a potential reservoir for C. difficile, and while studies have shown that swine and farm workers can be colonized with identical clones of C. difficile, the zoonotic transmission of C. difficile from livestock to people has not been definitively demonstrated. The goal of this study was to determine whether dairy calves and dairy farm workers harbored genetically similar isolates of C. difficile. First, we validated a glove juice protocol for detecting C. difficile on farm workers' hands. We then visited 23 farms and collected 1) fecal samples from 92 dairy calves, 2) hand rinsates from 38 dairy farm workers, and 3) fecal samples from five of the dairy farm workers who were willing to submit them. All samples underwent anaerobic culture and qPCR to detect C. difficile. C. difficile was detected on 15 of the farms (65.2%, 95% confidence interval (CI) 42.7%-83.6%) and in 28 calves (30.4%, 95% CI 21.2-40.9%) but in none of the hand rinsates or human fecal samples. Thus, the zoonotic transmission of C. difficile on dairy farms could not be demonstrated, and dairy farmers did not appear to be at increased risk of acquiring C. difficile via the fecal-oral route., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Contamination of meat with antimicrobial-resistant bacteria represents a major public health threat worldwide. In this study, we determined the antimicrobial resistance profiles and resistance trends of Staphylococcus aureus isolated from major food animal carcasses (408 cattle, 1196 pig, and 1312 chicken carcass isolates) in Korea from 2010 to 2018. Approximately 75%, 92%, and 77% of cattle, pig, and chicken carcass isolates, respectively, were resistant to at least one antimicrobial agent. Resistance to penicillin (62.1%) was the highest, followed by resistance to tetracycline (42.1%) and erythromycin (28.2%). About 30% of pig and chicken isolates were resistant to ciprofloxacin. We observed linezolid resistance only in pig isolates (2.3%). However, all S. aureus isolates were sensitive to rifampin and vancomycin. We noted an increasing but fluctuating trend of kanamycin and penicillin resistance in cattle isolates. Similarly, the chloramphenicol, ciprofloxacin, tetracycline, and trimethoprim resistance rates were increased but fluctuated through time in pig isolates. Methicillin-resistant S. aureus (MRSA) accounted for 5%, 8%, and 9% of the cattle, pig, and chicken isolates, respectively. The MRSA strains exhibited significantly high resistance rates to most of the tested antimicrobials, including ciprofloxacin, erythromycin, and tetracycline compared with methicillin-susceptible S. aureus (MSSA) strains. Notably, a relatively high percentage of MRSA strains (5.2%) recovered from pig carcasses were resistant to linezolid compared with MSSA strains (2.1%). In addition, almost 37% of the isolates were multi-drug resistant. S. aureus isolates recovered from major food animal carcasses in Korea exhibited resistance to clinically important antimicrobials, posing a public health risk.