Antibiotic treatments

Drug resistance in the defined sense, however, is not always the reason for treatment failures. The formation of biofilms may be as well regarded as a resistance mechanism. Cells within such a film withstand the antibiotic treatment. Some antibiotics (e.g. the aminoglycoside tobramycin) penetrate only slowly into the film. A further explanation is the existence of cells living in a non-growing, protected phenotypic state. 

Furthermore, the inability of the drug to reach the focus of the infection or to reach bacteria with intracellular location may be a common reason for the failure of antibiotic treatment. 

Treat acute bacterial conjunctivitis with broad-spectrum antibiotics. Although the condition is usually self-limiting, antibiotic treatment decreases the spread of disease to other people and prevents extraocular infection. Additionally, treatment may help decrease the risk of corneal ulceration or other complications that affect sight. Finally, treatment speeds recovery.14... 

Patients with chronic bacterial conjunctivitis often have a concurrent case of blepharitis. Add a lid hygiene regimen to topical antibiotic treatment.12... 

Once the temperature is normal for 48 to 72 hours and the patient is eating, consider changing the IV antibiotic to an oral regimen for the duration of antibiotic treatment. Monitor the serum creatinine level to evaluate for renal complications as... 

Mader JT, Shirtliff ME, Bergquist SC, Calhoun J. Antibiotic treatment of chronic osteomyelitis. Clin Orthop Relat Res 1999 360 47-65. 

MacArthur RD, Miller M, Albertson T, et al. Adequacy of early empiric antibiotic treatment and survival in severe sepsis experience from the MONARCS trial. Clin Infect Dis 2004 38 284-288. 

Effect of livestock breed and husbandry (including veterinary antibiotic treatments) on the incidence of pathogens and antibiotic-resistant bacteria... 

The objective of mastitis treatments is to cure the infected udders from the infection, but cure is defined in very different ways. For example, in economic terms, the farmer needs to achieve a level of udder health that allows expected milk yields and quality parameters specified by processors/ national regulations to be achieved. On the other hand, cure with respect to antibiotic treatments, is often defined in terms of absence of bacterial pathogens in milk (bacterial cure), with the proportion of cows without detectable pathogen presence following treatment being defined as the bacterial cure rate (BCR). The main problem with using BCR as the main indicator of cure is that it was frequently shown to include a proportion of cows with drastically elevated SCC values (indicative of sub-clinical mastitis) after treatment, but without clinical (sensory) symptoms. 

The objective of antibiotic treatments is to reduce the density of microbial pathogen in infected udder tissues and thereby improve the capacity of the animal s immune system to deal with the infection. The effect of a successful antibiotic treatment is therefore self-cure of mastitis (Hamann and Kromker, 1999). However, some antibiotics (e.g. tetracycline and gentamycine) may also have negative side effects on the animal s immune response to udder infection, as they have been shown to inhibit/reduce phagocytosis of the animal s own defence cells (Nickerson et al 1986). 

Given the diversity of disease-causing organisms, the interactions between farm-specific environmental factors and the types of mastitis causing pathogens found, the potential efficacy of antibiotic treatments can only be assessed accurately in the context of the specific on-farm conditions. Furthermore, many recent investigations concluded that, except for some specific infections caused by streptococci, a prophylactic and or longer-term use of antibiotics for chronic and sub-clinical mastitis should not recommended in the future (Deluyker et al., 2005). 

However, in case of acute clinical mastitis, it is widely accepted that animal welfare considerations should take prevalence. If both farmer and veterinarian are not familiar with non-antibiotic treatments, they should be advised to use broad-spectrum antibiotics immediately, because any delay (e.g. the 2-3 days it often takes between diagnosis and the return of microbiological test results) may seriously harm the animal. This approach should, however, only be taken after a sound clinical diagnosis, since antibiotic treatments themselves may lead to dramatic aggravation of the condition. For example, E. coli inflammations are able to develop into severe toxaemia, because increased levels of toxins are released into the animal tissues when E. coli cells are killed or stressed by antibiotic treatments. Also, if yeasts are the main cause or form part of the pathogen complex that causes mastitis, their growth and proliferation may be supported by the administration of anti-bacterial antibiotics (Crawshaw et al., 2005). 

Crawshaw, W.M., MacDonald, N.R. and Duncan, G. (2005), Outbreak of Candida rugosa mastitis in a dairy herd after intramammary antibiotic treatment . Veterinary Record, 156, 812-813. 

Hektoen, L., Larsen, S., Odegaard, S.A. and Loken, T. (2004), Comparison of homeopathy, placebo and antibiotic treatment of clinical mastitis in dairy cows - methodological issues and results from a randomized-clinical trial. Journal of Veterinary Medicine A Physiology, Pathology and Clinical Medicine, 51, 439-446. 

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