The spread and antimicrobial resistance of Staphylococcus aureus in South African dairy herds - A review.

Staphylococcus aureus is internationally recognised as a principal agent of mastitis and the foremost reason for economic loss in the dairy industry. The limited data available on organism-specific antibiotic resistance surveillance in dairy cattle have stimulated the need for such a review article. The objective of this study was to review relevant literature on antimicrobial resistance of mastitis-causing staphylococci isolated from dairy cows in South Africa compared to other countries.

Surveillance of Antibiotic Resistance of Maltose-Negative in South African Dairy Herds.

Antibiotic resistance has been reported since the 1940s in both human and veterinary medicine. Many years of monitoring milk samples in South Africa led to identification of a novel maltose-negative ( strain, which appears to be an emerging pathogen. In this study, the susceptibility of this strain to antibiotics was evaluated over time, during diverse seasons in various provinces and according to somatic cell count (SCC) categories.

Climatic and regional antibiotic resistance patterns of Staphylococcus aureus in South African dairy herds.

South Africa is a large country of approximately 1.22 million km2, made up of nine provinces with three climatic zones. Farming in the country is mostly defined by regional differences.

Proactive udder health management in South Africa and monitoring of antibiotic resistance of Staphylococcus aureus; in dairy herds from 2001 to 2010.

Antibiotic resistance of strains of Staphylococcus aureus isolated from bovine milk is of concern internationally. The objective of this study was to investigate trends of resistance of S. aureus to antibiotics administered to dairy cows in 19 South African and one Zambian dairy herds (participating in the South African proactive udder health management programme) and to identify possible contributing factors.

Epidemiological and partial budget analysis for treatment of subclinical Staphylococcus aureus intramammary infections considering microbiological and cytological scenarios.

An innovative method was investigated to aid in the elimination of Staphylococcus aureus (S. aureus) intramammary infections (IMI) from dairy herds. A stochastic model explore the economic benefit of three-day or eight-day treatment of subclinical IMI in all S.

Validity of somatic cell count as indicator of pathogen-specific intramammary infections.

The objective of this study was to determine whether somatic cell count (SCC) was an effective test, with a sensitivity exceeding 85%, to determine species-specific bacterial infections. In addition, the relation between the SCC and various udder pathogen groups was investigated. SCC thresholds of greater than 200 000 cells/mL were used in quarter and greater than 150 000 cells/mL in composite milk samples.

Somatic cell count thresholds in composite and quarter milk samples as indicator of bovine intramammary infection status.

The objective of the study was to establish an operational somatic cell count (SCC) threshold to predict the presence of intramammary infection (IMI) in composite milk samples and compare findings with those in quarter milk samples. South African dairy producers now preferred composite milk samples for herd udder health analysis because of increasing cow numbers, convenience of sampling and lower cost. A retrospective study was conducted on 345 461 composite and 89 638 quarter milk samples from South African herds.

A pathogen-specific approach towards udder health management in dairy herds: Using culture and somatic cell counts from routine herd investigations.

A dedicated udder health diagnostic programme was developed and used over a 15-year period in South Africa to analyse milk samples based on microbiological and cytological patterns within various groups and for individual cows and udder quarters in dairy herds. These pathogen-specific analyses are utilised for pro-active improvement and management of udder health in South African commercial dairy herds. The programme acts as a monitoring tool and identifies management areas at risk and individual cows with udder disease and uses both quarter and composite milk samples.

Assessment of acquired immune response to Rhipicephalus appendiculatus tick infestation in different goat breeds.

Changes in serum gamma globulin levels, numbers of replete female ticks and engorged tick mass were used as parameters to monitor the acquired immune response (antibody mediated immune response) elicited by Rhipicephalus appendiculatus adult tick infestations. Three consecutive Rhipicephalus appendiculatus adult tick infestations were applied to South African Indigenous goats (Nguni), Saanen goats and cross-bred goats (Saanen goats crossed with South African Indigenous goats [Nguni]) under laboratory conditions. During the three consecutive Rhipicephalus appendiculatus adult tick infestations the serum gamma globulin levels increased in all three breeds, whilst the mean replete female tick numbers and engorged tick mass decreased.

Parasites of domestic and wild animals in South Africa. XLVIII. Ticks (Acari: Ixodidae) infesting domestic cats and wild felids in southern Africa.

Ticks collected from domestic cats (Felis catus), cheetahs (Acinonyx jubatus),caracals (Caracal caracal), African wild cats (Felis lybica), black-footed cats (Felis nigripes), a serval (Leptailurus serval), lions(Panthera leo), and leopards (Panthera pardus) were identified and counted. Thirteen species of ixodid ticks and one argasid tick were identified from domestic cats and 17 species of ixodid ticks from wild felids. The domestic cats and wild felids harboured 11 ixodid species in common.