Chronic caprine mastitis in Nigerian goat breeds: microbiological flora and histopathological findings

Epidemiology and antimicrobial resistance of staphylococci other than Staphylococcus aureus from domestic animals and livestock in Africa: a systematic review

Introduction

Staphylococci other than Staphylococcus aureus (SOSA) in animals are becoming more pathogenic and antibiotic resistant and can potentially disseminate to humans. However, there is little synthesized information regarding SOSA from animals in Africa. This systematic review provides a comprehensive overview of the epidemiology and antimicrobial resistance of SOSA in companion animals (pets) and livestock in Africa.

Method

This systematic review (PROSPERO-CRD42021252303) was conducted according to the PRISMA guidelines, and 75 eligible studies from 13 countries were identified until August 2022. Three electronic databases (Pubmed, Scopus and Web of Science) were employed.

Results

The frequently isolated SOSA were S. epidermidis, S. intermedius, S. pseudintermedius, S. xylosus, S. chromogenes, S. hyicus, M. sciuri, S. hominis, and S. haemolyticus. Thirty (40%) studies performed antibiotic susceptibility testing (AST). Penicillin (58%) and tetracycline (28%) resistance were most common across all SOSA with high rates of resistance to aminoglycosides, fluoroquinolones, and macrolides in some species. Resistance to last-resort antibiotics such as linezolid and fusidic acid were also reported. Limited data on strain typing and molecular resistance mechanisms precluded analysis of the clonal diversity of SOSA on the continent.

Conclusion

The findings of this review indicate that research on livestock-associated SOSA in Africa is lacking in some regions such as Central and Western Africa, furthermore, research on companion animals and more advanced methods for identification and strain typing of SOSA need to be encouraged.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42021252303.

Animal-Based Indicators for On-Farm Welfare Assessment in Goats

Simple Summary

Welfare assessments for animals require the use of specific indicators. These indicators should be practical and easy to use in an on-farm environment while correctly reflecting on the animals’ welfare. Our aim was to review literature on such indicators for goats, as small ruminants have not received as much attention as other farm animals in the field of welfare assessment. Some indicators such as lameness are already well investigated and suitable for use in goat welfare assessments. Others, for example, lying behaviour, need more research, as the limited amount of knowledge restrains the information on validity or usefulness. As in other animals, the welfare of goats has become an increasingly important issue in public discourse. Our overview on indicators aids in developing tools to measure and improve the welfare of goats.

Abstract

This review describes the current state of knowledge relating to scientific literature on welfare indicators for goats. Our aim was to provide an overview of animal-based indicators for on-farm welfare assessments. We performed a literature search and extracted 96 relevant articles by title, abstract, and full-text screening. Out of these articles, similar indicators were aggregated to result in a total of 32 welfare indicators, some of which were covered in multiple articles, others in only a single one. We discuss a set of three established assessment protocols containing these indicators, as well as all individual indicators which were covered in more than one article. As single indicators, we identified lameness, body condition score (BCS), qualitative behaviour assessment (QBA), and human–animal relationship (HAR) tests with substantial evidence for sufficient validity to assess welfare in goats. A multitude of indicators (e.g., hair coat condition) was studied less intensively but was successfully used for welfare assessments. For some indicators (e.g., oblivion, lying behaviour), we highlight the need for future research to further validate them or to optimise their use in on-farm welfare assessments. Moreover, further investigations need to include kids, bucks, and meat and fibre goats, as well as extensively kept goats as the literature predominantly focuses on dairy goats in intensive production systems.

Multilocus sequence analysis reveals genetic diversity in Staphylococcus aureus isolate of goat with mastitis persistent after treatment with enrofloxacin

Staphylococcus aureus is one of the main bacterial agents responsible for cases of mastitis in ruminants, playing an important role in the persistence and chronicity of diseases treated with antimicrobials. Using the multilocus sequence typing technique, network approaches and study of the population diversity of microorganisms, we performed analyzes of S. aureus (ES-GPM) isolated from goats with persistent mastitis (GPM). The most strains of ES-GPM were categorically different phylogenetically from the others and could be divided into two lineages: one with a majority belonging to ES-GPM and the other to varied strains. These two lineages were separated by 27 nuclear polymorphisms. The 43 strains comprised 22 clonal complexes (CCs), of which the ES-GPM strains were present in CC133, CC5 and a new complex formed by the sequence type 4966. The genetic diversity of some alleles showed be greater diversity and polymorphism than others, such as of the aroE and yqiL genes less than glpF gene. In addition, the sequences ES-GPM to the arc gene and glpF alleles showed the greatest number of mutations for ES-GPM in relation to non-ES-GPM. Therefore, this study identified genetic polymorphisms characteristic of S. aureus isolated from milk of goats diagnosed with persistent mastitis after the failed treatment with the antibiotic enrofloxacin. This study may help in the future to identify and discriminate this agent in cases of mastitis, and with that, the most appropriate antibiotic treatment can be performed in advance of the appearance of persistent mastitis caused by the agent, reducing the chances of premature culling and animal suffering.

Study on prevalence, clinical presentation, and associated bacterial pathogens of goat mastitis in Bauchi, Plateau, and Edo states, Nigeria

Aim:

This study aimed to estimate the prevalence and clinical presentations of different forms of mastitis and mastitis-causing pathogens in lactating goats in Bauchi, Plateau, and Edo states, Nigeria.

Materials and Methods:

A total of 500 quarters from 250 lactating goats of Red Sokoto and West African Dwarf breeds during the lactation period were clinically examined. Clinical mastitis was detected by gross signs of udder infection during physical examination and abnormal milk, whereas subclinical mastitis (SCM) was recognized using California mastitis test. The bacterial pathogens were identified by morphology, hemolysis, gram staining, and biochemical tests such as catalase, oxidase, coagulase, reaction on sulfite, indole, and motile medium, and fermentation of sugars.

Results:

The overall prevalence of mastitis in goats was found to be 101 (40.4%), of which 8% (20/250) were clinical, and 32.4% (81/250) were SCM cases. The quarter level prevalence was 29.4% (145/493), comprising 5.9% (29/493) clinical and 23.2% (116/493) subclinical forms of mastitis. In addition, 1.4% (7/500) of teats were found to be blind on the clinical examination of the udder and teat. Several regional inflammatory reactions and abnormalities in milk were found in 69% and 100% of the cases, respectively. Moreover, some indications of generalized signs such as fever, reduction in appetite, increase in respiration, and pulse rate per minute were recorded in 100%, 75%, 85% and 80% of the cases, respectively. The predominant bacterial isolates recovered were Staphylococcus aureus (20.0%), followed by Escherichia coli (15.5%) and Streptococcus agalactiae (11.0%), and the least isolated microorganisms (≤6%) were bacteria of different species including Staphylococcus auricularis, Staphylococcus caprae, Staphylococcus chromogenes, Staphylococcus epidermidis, Staphylococcus hyicus, Staphylococcus xylosus, Staphylococcus lentus, Streptococcus dysgalactiae, Streptococcus pluranimalium, Streptococcus uberis, Streptococcus pneumoniae, Streptococcus ruminatorum, Streptococcus suis, Micrococcus luteus, Enterobacter cloacae, Proteus vulgaris, Klebsiella oxytoca, Klebsiella pneumoniae, Morganella morganii, Salmonella Typhimurium, Citrobacter freundii, Pseudomonas aeruginosa, Acinetobacter rudis, Acinetobacter haemolyticus, and Bacillus cereus.

Conclusion:

Mastitis continues to be recognized as one of the important health issues and leads to major economic losses to the dairy goats caused by many bacterial pathogens, and the effective measures need to be taken to control the disease.

Analysis of raw goat milk microbiota: impact of stage of lactation and lysozyme on microbial diversity

To protect infants from infection, human milk contains high levels of the enzyme lysozyme, unlike the milk of dairy animals. We have genetically engineered goats to express human lysozyme (hLZ milk) in their milk at 68% the amount found in human milk to help extend this protection. This study looked at the effect of hLZ on bacteria in raw milk over time. As the microbial diversity of goats' milk has yet to be investigated in depth using next-generation sequencing (NGS) technologies, we applied NGS and clone library sequencing (CLS) to determine the microbiota of raw goat milk (WT milk) and hLZ milk at early, mid and late lactation. Overall, in WT milk, the bacterial populations in milk at early and mid lactation were similar to each other with a shift occurring at late lactation. Both methods found Proteobacteria as the dominant bacteria at early and mid lactation, while Actinobacteria surged at late lactation. These changes were related to decreases in Pseudomonas and increases in Micrococcus. The bacterial populations in hLZ milk were similar to WT milk at early and mid lactation with the only significant differences occurring at late lactation with the elevation of Bacillaceae, Alicyclobacillaceae, Clostridiaceae and Halomonadaceae.

Sub-clinical mastitis and associated risk factors on lactating cows in the Savannah Region of Nigeria

BACKGROUND

Sub-clinical mastitis limits milk production and represents an important barrier to profitable livestock economics worldwide. Milk production from cows in Nigeria is not at optimum levels in view of many factors including sub-clinical mastitis.

RESULTS

The overall herd-level prevalence rate for SCM was 85.33% (256/300 heads of cows) while the quarter-level prevalence rate of SCM was 43.25% (519/1,200 quarters). The prevalence of SCM was 50.67%, 43.67%, 39.67% and 39.13% for the left fore-quarter, right hind-quarter, left hind-quarter and right fore-quarter, respectively. The Rahaji breed had the highest prevalence of SCM with 65.91% (29/44), while the White Fulani breed had the least with 32.39% (57/176). A total of 32.33% (97/300) had only one mammary quarter affected, 30.33% (91/300) had two quarters affected, 16.00% (48/300) had three quarters affected while 6.67% (20/300) had all the four quarters affected. A total of 53.00% had SCM in multiple quarters (159/300). The risk of SCM decreased significantly among young lactating cows compared to older animals (OR = 0.283; P < 0.001; 95%CI = 0.155; 0.516). The Rahaji breed had significantly higher risk compared with the White Fulani breed (OR = 8.205; P = 0.013; 95% CI = 1.557; 43.226). Improved sanitation (washing hands before milking) will decrease the risk of SCM (OR = 0.173; P = 0.003; 95% CI = 0.054; 0.554).

CONCLUSION

SCM is prevalent among lactating cows in the Nigerian Savannah; and this is associated with both animal characteristics (age, breed and individual milk quarters) and milking practices (hand washing).Good knowledge of the environment and careful management of the identified risk factors with improved sanitation should assist farm managers and veterinarians in implementing preventative programmes to reduce the incidence of SCM.

Mastitis of sheep and goats

This article presents an overview of the recent research into ovine and caprine mastitis. The common clinical presentations of mastitis in these species are reviewed, as are the important etiologic agents and their significance. The interpretation of somatic cell counts and surrogate tests, factors that affect somatic cell count levels, and association of somatic cell count levels with productivity are reviewed. Investigations into the treatment and prevention of mastitis and milking equipment function are discussed, and comments are made on the public health implications of extra label drug use and the consumption of unpasteurized milk.