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Molecular Microbiology Research (Online) 2012, Vol.2 No.1 1-9
ISSN 1027-5595
http://mmr.sophiapublisher.com
5
parental of medicinal products to treat mastitis is an
important issue and relative interest of each route
mainly depends on location of bacteria in udder and
physicochemical properties of therapeutic molecule.
Bacteriological cures reduced with: 1. Increase age of
cow; 2. In early lactation; 3. Severity of infection; 4.
No. of quarter affected; 5. In hind quarters; 6. With
shorter duration of treatment.
However after intra-mammary infusion many factors
affect udder tissue concentration like lipid solubility,
tissue protein binding of drug, pH of milk,
inflammatory exudate at the site (Table 2; Table 3).
Table 2 Milk: Plasma concentration for some antimicrobials
used in the treatment of bovine mastitis (Rasmussen, 1996; Ziv,
1980)
Antimicrobials
Lipid solubility
Ratio
Organic acids
Penicillin-G
Low
0.13
-
0.26
Cephaloridine
Low
0.24
-
0.28
Sulphademethoxine
Moderate
0.21
Weak bases
Tylosin
High
3.5
Erythromycin
Very high
8.7
Aminoglycosides
Low
0.5
Trimethoprime
High
2.9
polymyxin
Very low
0.3
Amphoteric
Oxytetracycline
Moderate
0.75
Doxycycline
Moderate/high
1.53
Table 3 Plasma protein bindings of antimicrobials in bovines
(Srivastava, 2000)
7 Selection of Therapy Regimens for Mastitis
7.1 Selection of antibiotic
Practical consideration to be taken in to account in
relating the time course of antibiotic concentration in
milk and udder to potentiate cilinical and
bacteriological efficacy after parentral and intra
mammary administration.
Streptococcus uberis
infection treated with Penethamate systemic route
shows bacteriological cure rate of 76.4% whereas intra
mammary with 1 g procaine penicillin+ 0.05 g
dihydrostreptomycin achieves 84.9% bacteriological
cure. This depicts significantly better efficacy of intra
mammary treatment against systemic in coagulase
negative staphylococci infection (Mc Dougall, 1998).
Weakly acidic antibiotic are present in milk at low
concentration than serum but their distribution shifted
in udder in mastitis, reverse is also true for basic
drugs.Mean tissue concentration of penethamate and
macrolids 8 times higher than in plasma in normal
milk which reduces with mastitis.
Sulpha drug and Penicillin-G, Ampicilin, Cloxacillin,
Cephalosporins concentration increases in mastitis
which is poorly in normal milk. OTC having high
MIC against
S. aureus
whereas Gentamycin,
Kanamycin have lower one and hence maintains
effective concentration for 8~12 hours.
7.2 Selection of route of administration
7.2.1 Duration of treatment
For effective therapy of mastitis antibiotic must be
administered repeatedly for 5~7 days (Rasmussen and
sulman, 1996).
7.2.2 Route of treatment
(A) Intra mammary
Majority of antibiotics instigated to cross blood-milk
barrier by passive diffusion, and non ionized fraction
of them is usually more lipid soluble hence easily
penetrate through passive diffusion. This is a route of
choice in mild cases. Sequence of events occurs after
intra mammary administration (Ziv, 1985).
(1)
Pharmaceutical phase
This phase is important for bio-availability depends on
type of vehicle (aquous, gelatineous, oil, or use of
suspending agents, particle size, solubility).
Antimicrobials
Extent of binding (%)
Sulphadiazine
24
Sulphisoxazole
76
Sulphadimethoxine
83
Benzyl Penicillin
48
Chloramphenicol
30
Lincomycin
34
Kanamycin
4
Sulphadimidine
55