Bovine Mastitis Research Articles

Short communication: Association between prepartum subclinical magnesium imbalance and postpartum diseases in grazing dairy cows in Southern Chile.

This study aimed to evaluate the relationship between prepartum subclinical hypomagnesemia (pre-SHMg) and the occurrence of dystocia, metritis, clinical mastitis, lameness, and subclinical hypomagnesemia postpartum (post-SHMg) in pasture-based dairy cows. Also, the difference in means of prepartum magnesium (Mg) concentration by postpartum health events was evaluated. A total of 890 dairy cows from 32 commercial farms located in southern Chile were enrolled. Cows were examined twice, once between 30 and 3 days before and once between 3 and 30 days after calving. Blood samples were collected on both assessments, and cows were considered as having SHMg if serum total Mg < 0.65 mmol/L. On the postpartum visit, cows were evaluated for metritis and lameness. Information about clinical mastitis and dystocia was collected from on-farm records. Data were analyzed using multivariable mixed linear models and multivariable mixed logistic regression models. The overall prevalence of pre-SHMg was 9.9%, and its presence was associated with the occurrence of post-SHMg (odd ratio [OR] = 5.7; P < 0.0001) and metritis (OR = 3.1; P = 0.04). However, we did not detect an association between pre-SHMg and dystocia, clinical mastitis, or lameness after calving. Prepartum serum Mg concentrations were lower in cows that developed post-SHMg than those that did not (LSM ± SE = 0.75 ± 0.02 mmol/L vs. 0.83 ± 0.02 mmol/L; P < 0.0001). In conclusion, pre-SHMg was associated with a higher risk of post-SHMg and metritis in grazing dairy cows but not other postpartum health events.

Prevalence, antimicrobial susceptibility profiles and resistant gene identification of bovine subclinical mastitis pathogens in Bangladesh

Subclinical mastitis (SCM), a silent threat in the dairy sector of Bangladesh poses a significant economic impact and serves as a potential source of infection for healthy cows, hindering efforts to achieve milk self-sufficiency. Despite the importance of this issue, limited research has been conducted on mastitis in Sylhet region of Bangladesh. This study aimed to investigate the molecular prevalence, antimicrobial susceptibility profile and resistant genes detection on pathogens (Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae) causing SCM. In a cross-sectional study utilizing convenience sampling, 325 milk samples were collected from apparently healthy dairy cows. Initially, SCM was detected using the modified Whiteside test (MWST) method. Suspected positive samples were then subjected to bacteriological culture and standard biochemical assays, followed by molecular identification through polymerase chain reaction (PCR). Finally, antimicrobial susceptibility testing was conducted on all PCR-positive samples using the Kirby-Bauer disk diffusion method on Mueller-Hinton agar. In the Sylhet district, the prevalence of SCM was 64.92 % (211 out of 325) at the individual animal level and 82.69 % (43 out of 52) at the herd level. Among the SCM-positive animals, S.aureus was found in 31.75 % (67 out of 211) of cases, E.coli in 81.99 % (173 out of 211), and K.pneumoniae in 66.82 % (141 out of 211). K.pneumoniae had the highest prevalence at 60 % in Zakiganj, S.aureus at 45 % in Zakiganj, and E.coli at 72 % in Bishwanath Upazila. Extended spectrum beta lactamase (ESBL) genes blaTEM, blaOXA, blaCTX-M1,blaCTX-M2,MultiCaseDHA were identified. Additionally, antibiotic resistance genes tet(A), AAC(3)-iv, and Sul1 were also detected. The pathogens exhibited resistance to Penicillins (ampicillin, amoxicillin), Cephems (cefuroxime, ceftazidime), and Tetracyclines (tetracycline). However, all three bacteria were highly sensitive to meropenem, amikacin, gentamicin, ciprofloxacin, and sulfamethoxazole-trimethoprim. These findings highlight the critical need for targeted antimicrobial stewardship and effective control measures to mitigate the impact of SCM on dairy production and animal health in the Sylhet region of Bangladesh.

Virulence Determinants of Buffalo Mastitis Originated Streptococcus agalactiae Isolates

Streptococci as a cause of mastitis have become the major concern to the dairy industry worldwide due to huge economic losses. Streptococcus agalactiae is a major contagious mastitis pathogen and continues to be a major cause of mastitis in dairy cattle and buffaloes. The aim of the study was to investigate the virulence determinants of S. agalactiae strains isolated from buffalo milk. Within the scope of the study, 24 S. agalactiae isolates from buffalo mastitis were examined. Biofilm production of isolates was investigated phenotypically by CRA method. It was observed that 18 (75%) isolates were positive for biofilm production. The presence of hylB, fnbB, scpB and spb1 virulence genes in S. agalactiae isolates were investigated by PCR. It was determined that 19 (79.17%) of the isolates were positive for scpB and 6 (25%) for fnbB virulence genes. None of the isolates were found to contain hylB and spb1 virulence genes. The antibiotic resistance profiles of the isolates among kanamycin, ampicillin, enrofloxacin, erythromycin, tetracycline, trimethoprim-sulfamethoxazole antibiotic discs were determined by Kirby Bauer Disc Diffusion Method. Resistance were evaluated as % 41.7, % 45.9, % 25, % 12.5, % 20.9, and % 33.3, respectively. RAPD-PCR patterns of all isolates were determined using the ERIC-2 primer. The dendrograms of the RAPD patterns were plotted with the UPGMA method. It was determined that the isolates showed similarity between 59-95%. In conclusion, the research confirms the prevalence of various virulence genes in S. agalactiae isolated from buffalo mastitis. Further studies are therefore necessary to determine the molecular epidemiology and variability of S. agalactiae isolated from buffaloes, with the aim of improving mastitis control programs with regard to S. agalactiae.

Antimicrobial activity of chitosan and combination with antibiotics against mastitis-causing pathogens

Bovine mastitis (BM), primarily caused by bacterial pathogens infecting mammary glands, stands as the most prevalent disease in dairy cattle. Traditionally, antibiotics have been the primary choice of treatment, yet their overuse has led to widespread resistance and the presence of antibiotic residues in dairy products. Today, chitosan has emerged as a promising alternative in dairy farming. In this study, we systematically screened and assessed the antibacterial efficacy of five chitosan preparations of different viscosities and components. Additionally, we explored the synergistic antimicrobial potential of the most potent chitosan sample in combination with commonly employed antibiotics, including ampicillin, amoxicillin, oxacillin, and levofloxacin against four prevalent BM-causing pathogens: Staphylococcus epidermidis, Streptococcus agalactiae, Streptococcus uberis and Pseudomonas sp. Agar well diffusion, micro-dilution, and checkerboard techniques were applied to assess the antimicrobial activity and interaction effect. Results indicated that, at a concentration of 1%, low and medium viscosity samples (samples 1, 2, 3) exhibited relatively low activity, compared to very low viscosity ones (samples 4, 5). Notably, sample 5, a combination of chitosan sample 1 with orange and grapefruit essential oils, demonstrated the most potent antibacterial activity with a minimal inhibitory concentration (MIC) of 19.53 mg/L against S. agalactiae, S. uberis and S. epidermidis and 78.13 mg/L against Pseudomonas sp.. Furthermore, the combination of this chitosan sample and antibiotics exhibited some synergistic interactions against BM-causing pathogens, as indicated by the fractional inhibitory concentration (FIC) values ranging from ≥ 0.5 to ≤ 1. While these effects were notable, they did not reach the threshold for strong synergism (FIC &lt; 0.5). In summary, our study highlighted the high antibacterial activity of low viscosity chitosan, particularly in combination with essential oils. Although there were observed synergistic effects with antibiotics against BM-causing pathogens, the strength of these interactions was not robust enough to conclusively categorize them as strongly synergistic. Chitosan, however, emerges as a promising agent in the ongoing exploration of alternatives to antibiotics in the management of BM in dairy farming.

Application of MALDI-TOF MS to Identify and Detect Antimicrobial-Resistant Streptococcus uberis Associated with Bovine Mastitis.

Streptococcus uberis is a common bovine mastitis pathogen in dairy cattle. The rapid identification and characterization of antimicrobial resistance (AMR) in S. uberis plays an important role in its diagnosis, treatment, and prevention. In this study, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to identify S. uberis and screen for potential AMR biomarkers. Streptococcus uberis strains (n = 220) associated with bovine mastitis in northern Thailand were identified using the conventional microbiological methods and compared with the results obtained from MALDI-TOF MS. Streptococcus uberis isolates were also examined for antimicrobial susceptibility using a microdilution method. Principal component analysis (PCA) and the Mann-Whitney U test were used to analyze the MALDI-TOF mass spectrum of S. uberis and determine the difference between antimicrobial-resistant and -susceptible strains. Using MALDI-TOF MS, 73.18% (161/220) of the sampled isolates were identified as S. uberis, which conformed to the identifications obtained using conventional microbiological methods and PCR. Using PCR, antimicrobial-resistant strains could not be distinguished from antimicrobial-susceptible strains for all three antimicrobial agents, i.e., tetracycline, ceftiofur, and erythromycin. The detection of spectral peaks at 7531.20 m/z and 6804.74 m/z was statistically different between tetracycline- and erythromycin-resistant and susceptible strains, respectively. This study demonstrates a proteomic approach for the diagnosis of bovine mastitis and potentially for the surveillance of AMR among bovine mastitis pathogens.

Light-activated conjugated polymer nanoparticles to defeat pathogens associated with bovine mastitis

Bovine mastitis (BM) represents a significant challenge in the dairy industry. Limitations of conventional treatments have prompted the exploration of alternative approaches, such as photodynamic inactivation (PDI). In this study, we developed a PDI protocol to eliminate BM-associated pathogens using porphyrin-doped conjugated polymer nanoparticles (CPN). The PDI-CPN protocol was evaluated in four mastitis isolates of Staphylococcus and in a hyper-biofilm-forming reference strain. The results in planktonic cultures demonstrated that PDI-CPN exhibited a bactericidal profile upon relatively low light doses (∼9.6 J/cm2). Furthermore, following a seven-hour incubation period, no evidence of cellular reactivation was observed, indicating a highly efficient post-photodynamic inactivation effect. The successful elimination of bacterial suspensions encouraged us to test the PDI-CPN protocol on mature biofilms. Treatment using moderate light dose (∼64.8 J/cm2) reduced biofilm biomass and metabolic activity by up to 74% and 88%, respectively. The impact of PDI-CPN therapy on biofilms was investigated using scanning electron microscopy (SEM), which revealed nearly complete removal of the extracellular matrix and cocci. Moreover, ex vivo studies conducted on bovine udder skin demonstrated the efficacy of the therapy in eliminating bacteria from these scaffolds and its potential as a prophylactic method. Notably, the histological analysis of skin revealed no signs of cellular degeneration, suggesting that the protocol is safe and effective for BM treatment. Overall, this study demonstrates the potential of PDI-CPN in treating and preventing BM pathogens. It also provides insights into the effects of PDI-CPN on bacterial growth, metabolism, and survival over extended periods, aiding the development of effective control strategies and the optimization of future treatments.

Stable flies are bona fide carriers of mastitis-associated bacteria.

Disease prevention on dairy farms has significant implications for cattle health, food security, and zoonosis. Of particular importance is the control of bovine mastitis, which can be caused by diverse bacteria, including Klebsiella, Escherichia coli, Streptococcus, and Staphylococcus spp. Despite being one of the most significant and costly cattle diseases worldwide, the epidemiology of bovine mastitis is not well understood. This study provides parallel culture-independent and culture-dependent evidence to support the carriage of opportunistically pathogenic bacteria by Stomoxys flies on dairy farms. We further show that the fly microbiota is enriched in clinically relevant taxa-the vast majority of which can be traced to the manure habitats in which flies breed. Altogether, our results identify biting flies as underrecognized carriers of bacterial taxa associated with environmental bovine mastitis and other opportunistic infections in vertebrates and offer important insights into mechanisms of microbial acquisition by these and other medically important insects.

Natural sanitizers pre- and post-milking in the prevention of bovine mastitis

Approaches focused on improving animal health are essential strategies to increase the quality and productivity of the livestock sector. Bovine mastitis is a prevalent disease in dairy farming worldwide. There are various ways to prevent infections and mammary inflammation in cows, such as using sanitizers or disinfectants before and after milking to clean the cow's udder surface and reduce contamination. Chlorine-based disinfectants are commonly used, and in some cases, antibiotics are used to prevent mastitis. This review aimed to analyze scientific articles that used plants as a sanitizer for a cow's udder in the last 5 years. There were few records of experiments with plants for disinfecting cows' udders; a total of 10 articles and 12 plant species were mentioned, including twice Piper betle and Acacia nilotica. Among the classes of metabolites indicated as active are terpenoids, flavonoids, and tannins. Studies indicate that plant extracts exhibit antimicrobial properties. Plant-based disinfectants promote sustainable and environmentally friendly sanitation in the livestock production sector, as these products are biodegradable and renewable.

Virulence and resistance profiling of Staphylococcus aureus isolated from subclinical bovine mastitis in the Pakistani Pothohar region

Mastitis is considered one of the most widespread infectious disease of cattle and buffaloes, affecting dairy herds. The current study aimed to characterize the Staphylococcus aureus isolates recovered from subclinical mastitis animals in Pothohar region of the country. A total of 278 milk samples from 17 different dairy farms around two districts of the Pothohar region, Islamabad and Rawalpindi, were collected and screened for sub clinical mastitis using California Mastitis Test. Positive milk samples were processed for isolation of Staphylococcus aureus using mannitol salt agar. The recovered isolates were analyzed for their antimicrobial susceptibility and virulence genes using disc diffusion and PCR respectively. 62.2% samples were positive for subclinical mastitis and in total 70 Staphylococcus aureus isolates were recovered. 21% of these isolates were determined to be methicillin resistant, carrying the mecA gene. S. aureus isolates recovered during the study were resistant to all first line therapeutic antibiotics and in total 52% isolates were multidrug resistant. SCCmec typing revealed MRSA SCCmec types IV and V, indicating potential community-acquired MRSA (CA-MRSA) transmission. Virulence profiling revealed high prevalence of key genes associated with adhesion, toxin production, and immune evasion, such as hla, hlb, clfA, clfB and cap5. Furthermore, the Panton-Valentine leukocidin (PVL) toxin, that is often associated with recurrent skin and soft tissue infections, was present in 5.7% of isolates. In conclusion, the increased prevalence of MRSA in bovine mastitis is highlighted by this study, which also reveals a variety of virulence factors in S. aureus and emphasizes the significance of appropriate antibiotic therapy in combating this economically burdensome disease.

Biomarkers for subclinical bovine mastitis: a high throughput TMT-based proteomic investigation.

Mastitis represents the biggest threat to the health and productivity of dairy cows, leading to substantial economic losses in milk production. It manifests in two forms: clinical mastitis, easily diagnosed by visible symptoms, and subclinical mastitis (SCM), which lacks overt clinical signs. SCM's elusive nature often results in it going undetected, thus facilitating the spread of the disease-causing agent due to lack of treatment. Finding a reliable biomarker for early SCM would reduce the possibility of mastitis spreading in the herd, reduce the need for antibiotic use and ultimately reduce milk losses for producers. Utilizing state-of-the-art proteomics techniques, 138 milk samples from dairy cows in continental Croatia underwent analysis. These samples were categorized into four groups based on the Zagreb Mastitis Test (ZMT) and microbiological analysis: lowSCC- (n = 20), lowSCC + (n = 20), medSCC + (n = 79), and highSCC + (n = 19). A total of 386 proteins were identified and quantified, with 76 proteins showing significant differential abundances among the groups. Many of these proteins are linked to the innate immune system, as well as neutrophil and platelet degranulation processes. Through fold changes observed between groups, 15 proteins exhibiting biomarker characteristics for subclinical mastitis (SCM) were identified. Among these, five proteins-cathelicidins (-1, -4, and -7), lactoferrin, and haptoglobin-showed particular promise.

Clinical Evidence on Expansion of Essential Oil-Based Formulation's Pharmacological Activity in Bovine Mastitis Treatment: Antifungal Potential as Added Value.

Bovine mastitis, as a significant and prevalent health problem in dairy herds, is primarily attributed to bacterial infections. Yeasts, although considered relatively rare causative agents, have also been associated with mastitis in dairy cattle. Current mastitis treatment predominantly relies on antibiotics, with limited emphasis on antifungal treatment. However, mycotic mastitis is challenging to treat, since these fungi are often resistant to antibiotics and may even utilize them for energy. In the current research, the in vivo antimicrobial activity of the essential oil-based formulation (Phyto-Bomat), as a possible alternative mastitis treatment associated with yeasts, was studied. This study involved a total of 68 animals from two dairy farms with diagnosed mastitis, and three treatment groups were established: conventional antibiotic treatment, Phyto-Bomat treatment, and the combination of both. The findings suggest significant variations in the presence of Candida samples based on the treatment administered, and the most significant difference was noted in cows treated with the combination (Phyto-Bomat and antibiotics). Yet, it is important to note that the results reveal that, regardless of the treatment type, there are statistically significant differences in the presence of Candida samples across the examined time points. These results aim to provide valuable insights into the potential of EOs as an alternative therapy in bovine mastitis, specifically targeting yeasts. Such findings could offer new strategies in the mycotic mastitis control and reducing the occurrence of secondary infections following antibiotic treatment.

Point-of-need mastitis pathogen biosensing in bovine milk: From academic sample preparation novelty to industry prototype field testing

Bovine mastitis is an inflammation of the mammary gland, and it is the most common infectious disease in dairy cattle. Mastitis reduces milk yield and quality, costing dairy farmers millions of dollars each year. The aim of this study was to develop a point-of-need test for identifying mastitis pathogens that is field portable, cost-effective and can be used with minimal training. Using a proprietary polymer-based milk sample preparation method to rapidly extract pathogen DNA in milk samples, we demonstrated quantitative Polymerase Chain Reaction (qPCR) assays for six common bovine bacterial mastitis pathogens: Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Mycoplasma bovis and Escherichia coli. We also implemented this sample preparation method on a prototype point-of-need system in a proof-of-concept field trial to evaluate user experience. Importantly, the protype system enabled a sample-to-result turnaround time of within 70 min to quantitatively detect all six target pathogens. The key advantage of our point-of-need prototype system is being culture-independent yet providing automated milk sample preparation for molecular identification of key mastitis pathogens by non-expert users. Our point-of-need prototype system showed a good correlation to laboratory-based qPCR for target pathogen detection outcomes, thus potentially removing the need for milk samples to be transported off-site for laboratory testing. Above all, we successfully achieved our objective of developing a point-of-need biosensor technology for mastitis and increased its readiness level with industry partners towards technology commercialization.

Studi Kasus: Terapi Mastitis Klinis pada Sapi Perah di Kota Batu

The purpose of this case report is to report a case of clinical mastitis in dairy cattle in Batu. One case was reported on this period. Anamnesis was carried out, the owner revealed that the cow did not produce milk and when milking the udderand nipples felt hard and the milk that wanted to come out seemed to be stuck. Physical examination was carried out, cow’s weight ±400 kg, body temperature 38.4 °C, the udder and nipple were swollen and inflamed, and decrease of milk production, mammae showed reddish and asymmetrical and painful when palpate. Based on the history and physical examination of the cow, it can be concluded that the cow was diagnosed with clinical mastitis with a fausta prognosis and the differential diagnosis was mammary tumour. The therapy given in this case was injection of the antibioticInterspectin-L® 10 ml, the anti-inflammatory and antipyretic Tolfedine® 10 ml intramuscularly.

Chitosan-derivative nanoparticles loaded with dihydromyricetin: Characterization, antibacterial and antioxidant activities

Bovine mastitis is a global problem and is mainly treated with antimicrobial agents that can significantly affect milk quality and threaten human health. The mammary gland can be damaged by the accumulation of reactive oxygen species (ROS), particularly during the perinatal period. Dihydromyricetin (DHM) has a wide range of pharmacological activities and is considered safe. However, its poor solubility, absorption, and bioavailability have limited its application. To address this issue, we designed and synthesized new chitosan-derivative nanoparticles (HACC-NPs) loaded with DHM, which have the potential to overcome its bioabsorption problems and enhance its antibacterial and antioxidant effects. We used the emulsification/crosslinking method to load DHM into chitosan-derivative nanoparticles (DHM/HACC-NPs); then, SEM, TEM and FTIR analyses were used to show a denser, more tightly packed matrix for the DHM/HACC-NPs, which were successfully prepared. The size (176.4 nm), polydispersity index (PDI, 0.21), and absolute value of the zeta potential (+26.3 mV) confirmed the stability of the DHM/HACC-NPs. More importantly, DHM/HACC-NPs had a stronger antibacterial effect on S. aureus (MIC = 0.52 mg/mL and MBC = 1.02 mg/mL) than on E. coli (MIC = 1.02 mg/mL and MBC = 2.05 mg/mL). Notably, DHM/HACC-NPs were concentration-dependent scavengers of DPPH and hydroxyl radicals. In summary, DHM/HACC-NPs exhibited superior biocompatibility and antimicrobial and antioxidant activities, offering new insights into the development of a robust, udder-stable drug platform as a promising strategy for treating dairy cow mastitis.

Isolation and Molecular Confirmation of Staphylococcus aureus from Bovine Mastitis in Various Locations of Tamil Nadu, India

This present investigation was done for the Isolation and Molecular confirmation of Staphylococcus aureus from Bovine mastitis-infected cows in various Tamil Nadu, India locations. Two hundred milk samples, ranging from 15 to 20 ml, were collected aseptically from cows in farms in and around Tamil Nadu and surrounding areas after discarding the first few streaks of milk from 2021 to 2023. We used the CMT test to check the milk samples. Following a thorough mixing of the milk samples delivered to the laboratory, one loop containing the infected milk sample was plated on Nutrient agar and incubated at 37 ˚C for 18 to 24 hours. To identify the Staphylococcus aureus, the isolated bacterial colonies were preliminarily identified by Microscopic examination (Gram staining and Motility test), Plating in Selective medium (Mannitol Salt Agar) and Biochemical tests. The DNA of the bacteria was extracted and Polymerase Chain Reaction (PCR) was done to detect the presence of the nuc gene. Of the 200 milk samples obtained from nursing cows, 37.5 % were from Mastitis-positive animals; of these, 61.3 % were in the sub-clinical stage, while 38.7 % were in the clinical stage. Only 33 (16.5 %) of the 200 milk samples tested positive for Staphylococcus aureus. A total of 26 out of 75 animals (34.7 %) with Mastitis, and 7 out of 125 animals (5.6 %) without Mastitis. Fifteen (57.7 %) of the twenty-six Staphylococcus aureus isolates found in cows with mastitis were from clinical cases, whereas eleven (42.3%) were from sub-clinical cases. All of the Staphylococcus aureus isolates examined contained the 279 bp nuc gene, according to the conventional PCR findings. In conclusion, the research has shown that sub-clinical mastitis is more common than clinical mastitis and that Staphylococcus aureus was substantially more often isolated from mastitis milk, particularly in clinical instances.

Escherichia coli infection induces ferroptosis in bovine mammary epithelial cells by activating the Wnt/β-catenin pathway-mediated mitophagy

Iron overload causes mitochondrial damage, and then activates mitophagy, which may directly trigger and amplify ferroptosis. Our objective was to investigate whether Escherichia coli (E. coli) isolated from clinical bovine mastitis induces ferroptosis in bovine mammary epithelial cells (bMECs) and if so, the underlying regulatory mechanism. E. coli infection caused mitochondrial damage, mitophagy, and ferroptosis. Rapamycin and chloroquine increased and suppressed ferroptosis, respectively, in E. coli-treated bMECs. Moreover, E. coli infection activated the Wnt/β-catenin pathway, but foscenvivint alleviated it. In conclusion, E. coli infection induced ferroptosis through activation of the Wnt/β-catenin pathway-promoted mitophagy, and it also suppressed GPX4 expression.

Isolation, Characterization and In Vitro Evaluation of Novel Lytic Phages Active Against Staphylococcus aureus and Escherichia coli of Bovine Mastitis Origin

Isolation, Characterization and In Vitro Evaluation of Novel Lytic Phages Active Against Staphylococcus aureus and Escherichia coli of Bovine Mastitis Origin

Occurrence and characterization of multidrug-resistant extended spectrum β-lactamase producing Escherichia coli from bovine mastitis of Haryana

Occurrence and characterization of multidrug-resistant extended spectrum β-lactamase producing Escherichia coli from bovine mastitis of Haryana

Genes required for survival and proliferation of Mycoplasma bovis in association with host cells.

Mycoplasma bovis causes chronic bronchopneumonia, mastitis, arthritis, keratoconjunctivitis, and reproductive tract disease in cattle around the globe and is an emerging pathogen in bison. Control of mycoplasma infections is difficult in the absence of appropriate antimicrobial treatment or effective vaccines. A comprehensive understanding of host-pathogen interactions and virulence factors is important to implement more effective control methods against M. bovis. Recent studies of other mycoplasmas with in vitro cell culture models have identified essential virulence genes of mycoplasmas. Our study has identified genes of M. bovis required for survival in association with host cells, which will pave the way to a better understanding of host-pathogen interactions and the role of specific genes in the pathogenesis of disease caused by M. bovis.

Draft genome sequences of 148 Klebsiella pneumoniae species complex members from bovine and human hosts.

Klebsiella pneumoniae species complex members, particularly K. pnemoniae sensu stricto, are common bovine clinical mastitis pathogens and often the cause of hospital- and community-acquired infections in humans. Here, we present 148 draft genome assemblies and annotations of K. pneumoniae species complex members from bovine and human hosts in Canada.