VETERINARSKI ARHIV 68 (2), 51-57, 1998

ISSN 0372-5480
Printed in Croatia





Bovine and ovine mastitis in Dhuleil Valley of Jordan

Shawkat Q. Lafi*, and Nabil Q. Hailat

Department of Clinical Veterinary Sciences, Faculty of Veterinary Medicine,
Jordan University of Science and Technology, Irbid, Jordan





* Contact address:
Dr. Shawkat Q. Lafi,
Department of Clinical Veterinary Sciences, Faculty of Veterinary Medicine, Jordan University of Science and Technology, Irbid, P.O. Box 3030, Jordan,
Phone: 962 2 740-6081, Fax: 962 2 295123, E-mail: shqalafi@just.edu.jo


LAFI, S. Q., N. Q. HAILAT: Bovine and ovine mastitis in Dhuleil Valley of Jordan. Vet. arhiv 68, 51-57, 1998.

ABSTRACT

Milk samples obtained from 30 mastitic cows and 30 mastitic Awassi ewes were used to identify the aetiological agents of bovine and ovine mastitis in the Dhuleil Valley area of Jordan. Milk samples from 58 mastitic cow udder quarters and 51 ewe udder halves were collected. 92% of the samples gave positive results with the Whiteside test. Staphylococcus aureus, Streptococcus agalactiae, Escherichia coli, Corynebacterium bovis and Klebsiella spp. were the major causative agents of bovine mastitis. These micro-organisms were isolated in percentages ranging from 10% to 37%. Staphylococcus aureus, Streptococcus agalactiae, E. coli and Pseudomonas aeruginosa were the major cause of ovine mastitis, their percentages ranging from 7% to 50%. The sediment technique was superior (P<0.001) to the pre-culture incubated milk technique. Suggested control and preventive measures against bovine and ovine mastitis are discussed.

Key words: mastitis, sheep, cattle, bacteria, Jordan



Introduction

Mastitis, or inflammation of the mammary gland, is one of the most complex and costly diseases in the dairy industry (EBERHART et al., 1987). The disease is responsible for decreased milk production, increased veterinary and treatment costs, increased labour costs and increased culling (JANZEN, 1970; ASBY et al., 1975; DOBBINS, 1977; BLOSSER, 1979).

The widespread occurrence of the disease in dairy herds creates an estimated loss to producers of approximately $ 2 billion in the United States alone. This figure includes additional untold losses from altered milk quality and composition, and the effects on dairy products that occur once milk has left the farm (HARMON, 1994).

Application of hygienic measures determines the rate of infection in lactating animals. DODD (1983) noted infection in 50% of dairy cows where no hygiene or prevention program existed, while NATZKE et al. (1972) indicated a decrease of 7 to 8% of intramammary infection when effective hygiene, treatment of clinical quarters during lactation, and treatment of all quarters at drying off were used. SMITH (1990) reported that 62% of occurrences of clinical mastitis were due to environmental pathogens as coliform bacteria and most species of streptococci. The causative organisms of mastitis are categorised as major or minor pathogens (SCHALM et al., 1971; EBERHART et al., 1987; HOGAN and SMITH, 1987; HARMON, 1994). The most common major pathogens include Staphylococcus aureus, Streptococcus agalactiae, coliforms, streptococci and enterococci, while Corynebacterium bovis were considered to be minor pathogens.

In a field investigation of ovine mastitis in northern Greece, clinical mastitis was recorded in 11.4% of examined ewes. Mycoplasma spp. and Staphylococcus aureus were the major pathogens, as they were isolated from 45.9% and 38.5%, respectively, of mammary secretion samples, while coagulase-negative staphylococci, Pasteurella haemolytica, Escherichia coli, streptococci, Corynebacterium pyogenes, Bacillus spp. and Pseudomonas spp. were isolated at a lower rate (FTHENAKIS and JONES, 1990).

The objectives of this study were: (a) to determine the incidence of clinical mastitis in cows and ewes in Dhuleil Valley of Jordan, and (b) to isolate and identify the major udder pathogens.

Materials and methods

Samples and data collection

A total of 109 mastitis milk samples, representing 58 cows' milk and 51 ewes' milk, were collected from 30 cows and 30 ewes with cases of clinical mastitis, at the Dhuleil Valley region of Jordan between 1 January and 30 May 1996. Clinical mastitis was defined by the presence of abnormalities in the udder (signs of inflammation) or by abnormal udder secretions (flakes, clots or abnormalities in colour or consistency).

The teat of the affected quarter or half was carefully washed, dried and sterilised with Lugol's iodine solution. The teat orifice was then scrubbed with 70 % alcohol. Approximately 20 ml of milk were collected aseptically after rejecting the first stream of milk. Collected samples were cooled immediately and transferred to the laboratory in an ice box to be immediately examined or refrigerated for not more than 24 hours of sampling. Samples were not collected from animals treated with antibiotics by any route within 96 hours prior to collection.

Laboratory examination of milk

Each collected milk sample was divided and placed in two sterile plastic or glass containers (each half was about 5 ml). From the first 5 ml of each sample the Whiteside test, as recommended by BLACK BURN (1965), was performed to investigate the subclinical mastitis; on a clean glass slide, placed over a dark background, 5 drops of milk and 2 drops of NaOH 4% (normal solution) were mixed by sterile glass rod for 10 seconds and were examined for agglutination. Also, milk sediment was obtained by revolving half of each milk sample at 3000 rpm for 10 minutes. The other half of each collected milk sample was incubated overnight at 37 oC. Loopfuls of each sample of milk sediment and incubated milk were streaked over dried plates of the following media: Nutrient agar (Hi - Media PVT); 5% sheep blood agar (Becton Dickinson); McConkey agar (Hi Media Laboratories) and Sabouraud's agar (Mast Laboratories). All inoculated plates were incubated at 37 oC for 24 hours, except for Sabouraud's agar plates, which were incubated at 25 oC for 3-5 days.

For obtaining pure cultures, suspected colonies on incubated plates were identified and streaked over nutrient agar slants and incubated at 37 oC for 24 hours. On purified cultures, microscopical examination using Gram stain and biochemical identification was applied. Isolates of staphylococci, streptococci, coliforms, corynebacteria and Pseudomonas were biochemically identified according to CARTER et al. (1991). Cultures were considered to be positive when one or two species of bacteria known to cause mastitis were isolated, or when contagious mastitis pathogens, e.g., Staphylococcus aureus or Streptococcus agalactiae, were recovered - even in the mixture of environmental bacteria. Cultures were considered to be negative when no bacteria growth was observed on the culture plates. Cultures with three or more species, or when there was heavy growth of a mixture of environmental origin (environmental streptococci and coliforms), were considered as being contaminated.

Results and discussion

Mastitis is one of the most costly diseases affecting the dairy industry, as it is responsible for: decreased milk production, increased veterinary bills and treatment costs, higher labour costs and the culling of affected animals, in addition to altering the quality of produced milk.

One hundred (92%) of the examined milk samples were found to be positive using the Whiteside test (Table 1). This test is simple, rapid, gives satisfactory results and can be relied upon, as a field test, for the rapid detection of mastitis-affected milk (HARRIGAN and McCANCE, 1976).


Table 1. Results of the Whiteside test on examined milk samples from Jordan, 1996

Samples

Positive

%

Negative

%

Cows' milk (N=58)

53

91.4

5

8.6

Ewes' milk (N=51)

47

92.2

4

7.8

Total (N=109)

100

91.7

9

8.3

From the results shown in Table 2. It is clear that Staphylococcus aureus, Streptococcus agalactiae, E. coli, Corynebacterium bovis and Klebsiella spp. were the major bacterial isolates from bovine mastitis, where they could be isolated from 37%, 30%, 17%, 10% and 7% respectively, from the milk of examined cows. Similar results have been reported by a number of  researchers (DOBBINS, 1977; BARTLETT et al., 1992; DINSMORE et al., 1992; HARMON, 1994; LAFI et al., 1994).


Table 2. Causative agents of clinical mastitis in examined animals from Jordan, 1996

Causative microorganisms

Cows (N=30)

Ewes (N=30)

No. of animals

%

No. of animals

%

Staphylococcus aureus

11

36.7

15

50.0

Streptococcus agalactiae

9

30.0

8

26.7

E. coli

5

16.7

5

16.7

Corynebacterium bovis

3

10.0

-

-

Klebsiella spp.

2

6.6

-

-

Pseudomonas aeruginosa

-

-

2

6.6

Total

30

100

30

100

Staphylococcus aureus, Streptococcus agalactiae, E. coli and Pseudomonas aeruginosa were the main aetiological agents of mastitis in examined ewes, where they could be isolated from 50%, 27%, 17%, 7% of the milk of examined ewes, respectively (Table 2). These results agree with those presented by FTHENAKIS and JONES (1990), SMITH (1990), TOLA and ARBI (1990).

It is worth mentioning that yeasts fail to be detected in all examined samples. Pseudomonas aeruginosa failed to be isolated from the milk of mastitic cows, while Corynebacterium bovis and Klebsiella spp. failed to be recovered from the examined ewes' milk.

Frequency distribution of isolated organisms from the examined cows' and ewes' milk is shown in Table 3. Staphylococcus aureus (40%); Streptococcus agalactiae (28%); E. coli (17%); Corynebacterium bovis (10); Klebsiella spp. (3%) and Pseudomonas aeruginosa (3%).


Table 3. Frequency distribution of isolated organisms in cows and ewe milk samples from Jordan, 1996

Isolates

No.

%

Staphylococcus aureus

57

39.6

Streptococcus agalactiae

41

28.5

E. coli

24

16.7

Corynebacterium bovis

14

9.7

Klebsiella spp.

4

2.8

Pseudomonas aeruginosa

4

21.8

Total

144

100

In an attempt to increase the rate of recovery of pathogens, cultivation was carried out from milk sediment and pre-culture incubated milk. The superiority of the sediment technique over the pre-culture incubated milk technique in its ability to recover the aetiological agents of mastitis was proved (96/144 vs. 48/144) (X2=30, d.f=1, P < 0.001), where 67% of the isolated organisms could be recovered by the former vs 33% of the latter (Table 4). These results substantiate what has been recommended by DINSMORE et al. (1992). Our results showed that Staphylococcus aureus is the predominant cause of mastitis in cows and ewes, which may be due to the mechanism of virulence in staphylococcal infections and the ability of the organism to invade tissues rather than to excrete substances.


Table 4. Comparison between the sediment method and incubated milk method in the isolation of pathogens in the examined milk samples of cows and ewes from Jordan, 1996 (N=144)

Isolates

Sediment

Incubated

No.

%

No.

%

Staphylococcus aureus (N=57)

38

66.7

19

33.3

Streptococcus agalactiae (N=41)

26

63.4

15

36.6

E. coli (N=24)

19

79.0

5

21.0

Corynebacterium bovis (N=14)

8

56.0

6

43.0

Klebsiella spp. (N=4)

2

50.0

2

50.0

Pseudomonas aeruginosa (N=4)

3

75.0

1

25.0

Total

96

66.7

48

33.3

The contamination of milkers' hands, wash cloths, milking machine cups and bedding grounds may increase the incidence of both Staphylococcus aureus and Streptococcus agalactiae. The predominant position of Streptococcus agalactiae as a cause of clinical mastitis has been overtaken by Staphylococcus aureus, especially in those areas where the treatment of mastitis with penicillin has been practised intensively, and where machine milking has replaced hand milking.

Although Staphylococcus aureus is still pre-eminent as a cause of mastitis, its prevalence has been significantly curbed by modern control programmes based on teat dipping and dry period treatment. These programmes have also led to a higher proportion of bacteriological increases in infections by E. coli, Pseudomonas and Klebsiella spp. The shift in balance away from Gram-positive cocci to Gram-negative bacteria has been significant because they are resistant to hygienic control measures (RADOSTITS et al., 1994).

The recommended preventive and control measures against mastitis should include application of good sanitary and hygienic measures, such as adequate washing and sanitation of milkers' hands, wash cloths, milking machine cups and bedding. In addition to pre-milking washing and drying of the udder, post milking teat dip application, treatment of clinical quarters during lactation and treatment of quarters at drying off should be applied.

References

ASBY, C. B., P. R. ELLIS, T. K. GRIFFIN, R. G. KINGWILL (1975): The benefits and costs of a system of mastitis control in individual herds. Study No. 17, Natl. Inst. Res. Dairying, Shinfield, Reading, UK.

BARTLETT, P. P., G. Y. MILLER, S. E. LANCE, E. H. LAWRANCE (1992): Clinical mastitis and intramammary infection on Ohio dairy farms. Prev. Vet. Med. 12, 59-71.

BLACK BURN, P. S. (1965): A solution for use in assising the cell count of cow's milk. Br. Vet. J. 121, 154.

BLOSSER, T. H. (1979): Economic losses from and the national research program on mastitis in the United States. J. Dairy Sci. 62, 119-127.

CARTER, G. R., M. M. CHENGAPPA, G. WILLIAM (1991): Essentials of veterinary bacteriology and mycology. 4th ed. Philadelphia, London. pp. 109-237.

DINSMORE, R. P., P. B. ENGLISH, R. N. GONZALEZ, P. M. SEARS (1992): Use of augmented cultural techniques in the diagnosis of the bacterial cause of clinical bovine mastitis. J. Dairy Sci. 75, 2706-2712.

DOBBINS, C. N. (1977): Mastitis losses. J. A. V. M. A. 170, 1129-1132.

DODD, F. H. (1983): Symposium: Advances in understanding mastitis. J. Dairy Sci. 66, 1773- 1780.

EBERHART, R. J., R. J. HARMON, D. E. JASPER, R. P. NATZKE, S. C. NICKERSON, J. K. RENEAU, E. H. ROW, K. L. SMITH, S. B. SPENCER (1987): Current concepts of bovine mastitis. 3ed. Natl. Mastitis Counc. Inc. Arlington, VA.

FTHENAKIS, C. G., E. J. JONES (1990): Incidence and aetiology of clinical ovine mastitis in flocks in central Macedonia, Greece. Deltiotis Ellinikis Ktiniatrikis Etairias. Vol. 41, 133-141.

HARMON, R. J. (1994): Physiology of mastitis and factors affecting somatic cell count. J. Dairy Sci. 77, 2103-2112.

HARRIGAN, W. F., M. E. McCANCE (1976): Laboratory Methods in Food and Dairy Microbiology. Academic Press. London, New York, San Francisco. pp. 15-112.

HOGAN, J. S., K. L. SMITH (1987): A practical look at environmental mastitis. Comp. Continuing Educ. Pract. Vet. 9, 341-344.

JANZEN, J. J. (1970): Economic losses resulting from mastitis: a review. J. Dairy Sci. 53, 1151-1155.

LAFI, S. Q., O. F. AL-RAWASHEH, K. I. EREIFEJ, N. Q. HAILAT (1994): Incidence of clinical mastitis and prevalence of subclinical udder infections in Jordanian dairy cattle. Prev. Vet. Med. 18, 89-98.

NATZKE, R. P., R. W. EVERTT, R. S. GUTHRIE, J. F. KEOWN, A. M. MEEK, W. G. MERRILL, S. J. ROBERTS, G. H. SCHMIDT (1972): Mastitis control program: effects on milk production. J. Dairy Sci. 55, 1256-1260.

RADOSTITS, O. M., BLOOD, D. C., GAY, C. C. (1994): The Diseases of Cattle, Sheep, Pigs, Goats and Horses. 8th ed. Bailliere Tindall. London. pp. 563-614.

SCHALM, O. W., E. J. CARROL, N. C. JAIN (1971): Bovine mastitis. Lea & Febiger. Philadelphia, P. A.

SMITH, M. C. (1990): Exclusion of infectious diseases from sheep and goat farms. The veterinary clinics of North America: food animal practice (USA). Vol. 6, 705-720.

TOLA, V., S. H. ARBI (1990): The presence of micro-flora in the udder of sheep and goats and its role in causing the mastitis. Buletini I Shkencava Zooteknike Vetrenare, 77-82.

Received: 4 September 1997
Accepted: 11 March 1998



LAFI, S. Q., N. Q. HAILAT: Mastitis u krava i ovaca u dolini Dhuleil u Jordanu. Vet. arhiv 68, 51-57, 1998.

SAZETAK

Radi utvrdivanja etiologije mastitisa na podrucju doline Dhuleil u Jordanu, uzeti su uzorci mlijeka iz upaljenog vimena 30 krava i 30 ovaca pasmine Awassi. Uzorci su uzeti iz 54 upaljene cetvrti vimena krava i 51 upaljene polovice vimena ovaca. 92% uzoraka mlijeka dalo je pozitivne rezultate u testu otkrivanja supklinickog mastitisa. Kao glavni uzrocnici mastitisa u krava dokazane su vrste Staphylococcus aureus, Streptococcus agalactiae, Escherichia coli, Corynebacterium bovis i Klebsiella spp. Ove bakterije izdvojene su u 10 do 37% uzoraka. Glavni uzrocnici mastitisa u ovaca bile su vrste Staphylococcus aureus, Streptococcus agalactiae, Escherichia coli i Pseudomonas aeruginosa, a izdvojene su u 7 do 50% uzoraka. Pretrazivanjem mlijecnog taloga nakon centrifugiranja dobiveni su bolji rezultati nego postupkom preinkubacije mlijeka. Razmotrene su mjere za kontrolu i preventivu mastitisa u krava i ovaca.

Kljucne rijeci: mastitis, ovca, govedo, bakterije, Jordan


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