Impact of low light laser therapy (LLLT) on microorganisms causing subclinical and clinical bovine mastitis

The aim of the study was to monitor the effects of radiation emitted by an alternative, non-pharmaceutical agent "infrared low laser radiation 830nm with 300mW" on the growth of microorganisms in vitro from milk of cows with elevated somatic cell count (SCC). Also, detectiom of microorganism diversification and SCC after the lead treatment in vivo by the laser. Twenty six samples showed mastitis where five were clinically mastitic and 21 were subclinically mastitic. From those, 9 cows were chosen to be treated (two from clinically mastitic cows and 7 from subclinical mastitic cows). The clinical mastitic cows showed swollen, hot and painful teat with no change in milk characterization and gradual decrease in milk yield. Two cows showed sudden drop in milk yield and 3 cows showed change in milk characters with gradual decrease in milk yield. The average of milk yield of tested cows was ranged from 7.8 -20L during the five days before LLLT, CMT results showed strong score 3 for the nine cows and the reading of mastit test ranged from 455-850 units. Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli)were the most predominant isolates. The two organisms were isolated as single pathogen in 30.7% and 26.9% respectively of the culture of milk samples and as co-pathen with Strept.agalacteae and L.hardjo (19.2% and 9.6% respectively). Leptospira hardjo was diagnosed as single pathogen in a rate of 15.3%. Antibiotic susceptibility test revealed that S.aureus and E.coli showed multidrug resistance, where all S.aureus (15 isolates) resistant to tetracyclin, neomycin, chloramphenicol, amikacin, lincomycin and colistin sulfate, 14 isolates were resisitant to ampicillin, erythromycin, sulfa/trimethoprim and gentamicin, 13 isolates resistant to clindmycin, 12 isolates resistant to cephalothin and 7 isolates resistant to ernofloxacin. On the other hand, all E.coli (12 isolates) resistant to tetracyclin and sulfa/trimethoprim, 11 isolates resitant to erythromycin, neomycin and chloramphenicol, 10 isolates resistant to ampicillin, amikacin and lincomycin, 9 isolates resistant to gentamycin, 8 isolates resistant to chloramphenicol and colistin sulfate, 7 isolates resistant to clindamycin and 4 isolates resistant to ernofloxacin The increase of milk yield of each cow and normal physical character was observed during the period of LLLT and the average milk yield ranged from 6.2L up to 20L in clinical mstitic cows and 11.4L up to 17L in subclinical mstitic cows. The CMT records was decreased (score 1) and the EC decreased at the end of LLLT ranged from330-450 units. No viable bacteria were reisolated by the end of LLLT and post LLLT (end of experiment) where the average milk yield ranged from 12 to 21L in clinical mastitic cows and from 20 to 21.4L in subclinical mastitic cows. The CMT records was negative (score 0) for both clinical and subclinical cows and the EC decreased at the end of LLLT ranged from 250 -220 units in clinical mstitic cows and from 277 to 220 in suclinical mastitic cows. It was concluded from this study that low light laser therapy opens new perspectives in the treatment of clinical and subclinical mastitis as an alternative, noninvasive, and may be of low cost method as if compared with antibiotic treatment. Lactation was not stopped post LLLT while antibiotic therapy lactation stopped for 10- 15 days post treatment to avoid antibiotic residues in milk, Also it is considered as alternative green medicine.