Prevalence and Risk Factors of Mastitis and Isolation, Identification and Antibiogram of Staphylococcus Species from Mastitis Positive Zebu Cows in Toke Kutaye, Cheliya, and Dendi Districts, West Shewa Zone, Oromia, Ethiopia

Figures & data

Figure 1 Map of Ethiopia showing the study areas (Dendi, Cheliya and Toke Kutaye districts) where milk samples were collected from Zebu cows. The map was sketched using ArcGIS 9 software (ArcGIS™ version 10.7, California, USA).

Table 1 Prevalence of Mastitis at the Cow and Quarter Level

Categories	Type of Mastitis
	Overall Prevalence of Mastitis (95% CI)	Prevalence of Clinical Mastitis (95% CI)	Prevalence of Subclinical Mastitis (95% CI)
Cow level (N1=404)	30.4 (26.0−35.2)	3.2 (1.7–5.4)	27.2 (22.9–31.9)
Quarter level (N2=1528)	8.4 (7.0–9.8)	1.1 (0.6–1.7)	7.3 (6.0–8.7)

Abbreviations: N1, number of cows; N2, number of patent teats; CI, confidence interval.

Table 2 Isolation Rate of Staphylococcus Species from Mastitic Quarters of Zebu Cows in the Study Areas

Type of Staphylococcus Species (No. of Isolates in CM, SCM, M)	% Isolation (95% CI) from Clinical Mastitis (N=16)	% Isolation (95% CI) from Subclinical Mastitis (N=111)	% Isolation (95% CI) from Overall Mastitis (N=127)
S. aureus (3,4,7)	18.75(4.1–45.6)	3.6 (1.0–9.0)	5.5(2.2–11.0)
S. intermedius (0,13,13)	0(0.00)	11.7(6.4–19.2)	10.2(5.6–16.9)
S. hyicus (0,19,19)	0(0.00)	17.1(10.6–25.4)	15.0(9.3–22.4)
CPS (3,36,39)	18.75 (4.1–45.6)	32.4(23.9–42.0)	30.7(22.8–39.5)
S. lentus (3,5,8)	18.75(4.1–4.7)	4.5 (1.5–10.2)	6.3(2.8–12.0)
S. sciuri (0,2,2)	0(0.00)	1.8(0.2–6.4)	1.6(0.2–5.6)
CNS(3,7,10)	18.75(4.1–4.7)	6.3(2.8–12.6)	7.9(3.8–14.0)
All species (6,43, 49)	37.5(15.2–64.6)	38.7(29.6–48.5)	38.6(30.1–47.6)

Abbreviations: CNS, coagulase negative Staphylococcus; CPS, coagulase positive Staphylococcus; CI, confidence interval; CM, clinical mastitis; M, overall mastitis cases; N, number of quarters; SCM, subclinical mastitis.

Table 3 Logistic Regression Analysis of Potential Risk Factors for the Occurrence of Mastitis in the Study Area

Risk Factors	Categories	No. of Animals Exam.	No. Positive (%)	Univariable			Multivariable
				OR	95% CI	P value	OR	95% CI	p value
District	Toke Kutaye	148	35 (23.65)	1.0	–	–	1.0	–	–
	Dendi	162	45 (27.78)	1.24	0.74–2.07	0.407	1.55	0.68–3.49	0.295
	Cheliya	94	43 (45.74)	2.19	1.56–4.73	0.004	1.68	0.73–3.85	0.224
Age	≤ 4 years	234	41 (17.52)	1.0	–	–	1.0	–	–
	≥ 7 years	103	36 (34.95)	2.53	1.49–4.28	0.001	1.88	0.91–3.91	0.089
	5–6 years	67	46 (68.66)	10.31	5.57–19.10	≤0.001	8.68	3.89–19.38	≤0.001
Stage of lactation	> 7 months (late)	48	9 (18.75)	1.0	–	–	1.0	–	–
	< 3 months (early)	297	92 (30.98)	1.94	0.90–4.18	0.089	3.51	1.29–9.51	0.014
	4–7 months (mid)	59	22 (37.29)	2.58	1.05–6.32	0.039	4.01	1.23–13.12	0.022
Number of parities	≤ 2 calves	119	18 (15.13)	1.0	–	–
	3 to 5 calves	211	52 (24.64))	1.84	1.02–3.31	0.044
	≥ 6 calves	74	53 (71.62)	14.16	6.95–28.86	≤0.001
Type of Housing	Separate pen	52	12 (23.08)	1.0	–	–	1.0	–	–
	Shared barn	352	111 (31.53)	1.53	0.78–3.04	0.219	2.61	1.01–6.74	0.047
Interval of cleaning bedding	Once a week	209	32 (15.31)	1.0	–	–	1.0	–	–
	< once a week	51	10 (19.61)	1.35	0.61–2.96	0.456	1.30	0.45–3.75	0.622
	> a week	144	81 (56.25)	7.11	4.31–11.73	≤0.001	7.96	3.73–17.00	≤0.001
Udder washing	Yes	101	11 (10.89)	1.0	–	–
	No	303	112 (36.96)	4.80	2.46–9.36	≤0.001
Type of floor	Concrete	326	98 (30.06)	1.0	–	–
	Muddy	78	25 (32.05)	1.10	0.65–1.87	0.732
Using towel	No	313	95 (30.35)	1.0	–	–
	Yes	91	28 (30.77)	1.02	0.61–1.69	0.939
Tick infestation	Yes	264	76 (28.79)	1.0	–	–
	No	140	47 (33.57)	1.25	0.80–1.94	0.321
History of the previous mastitis	No	221	21 (9.50)	1.0	–	–	1.0	–	–
	Yes	183	102 (55.74)	11.99	7.02–20.50	≤0.001	9.35	4.92–17.78	≤0.001

Abbreviations: CI, confidence interval; OR, odds ratio; No., number; Exam, examined.

Table 4 Antimicrobial Susceptibility Pattern of S. aureus, S. lentus, and S. sciuri Isolates

Antimicrobials	Antimicrobial Susceptibility Pattern of Staphylococcus Species
	S. aureus (n=7)				S. lentus (n=8)				S. sciuri (n=2)
	S	R	ND	I	S	R	ND	I	S	R	ND	I
Amoxicillin - Clavulanate	100	0	0	0	12.5	87.5	0	0	0	100	0	0
Ampicillin	85.7	14.3	0	0	0	87.5	12.5	0	0	100	0	0
Cefotaxime	100	0	0	0	12.50	87.5	0	0	0	100	0	0
Cefoxitin	0	0	100	0	0	87.5	12.5	0	0	100	0	0
Ciprofloxacin	100	0	0	0	100	0	0	0	100	0	0	0
Clindamycin	85.7	0	0	14.3	12.5	12.5	0	75	0	0	0	100
Daptomycin	100	0	0	0	100	0	0	0	100	0	0	0
Erythromycin	100	0	0	0	100	0	0	0	100	0	0	0
Gentamycin	100	0	0	0	100	0	0	0	100	0	0	0
Imipenem	100	0	0	0	12.5	87.5	0	0	0	100	0	0
Linezolid	100	0	0	0	100	0	0	0	100	0	0	0
Moxifloxacin	100	0	0	0	100	0	0	0	100	0	0	0
Mupirocin high level	85.7	14.3	0	0	100	0	0	0	100	0	0	0
Nitrofurantoin	100	0	0	0	100	0	0	0	100	0	0	0
Oxacillin	100	0	0	0	12.5	87.5	0	0	0	100	0	0
Penicillin-G	71.4	28.6	0	0	0	87.5	12.5	0	0	100	0	0
Rifampin	100	0	0	0	100	0	0	0	100	0	0	0
Teicoplanin	100	0	0	0	100	0	0	0	100	0	0	0
Tetracycline	100	0	0	0	100	0	0	0	100	0	0	0
Trimethoprim-sulfamethoxazole	100	0	0	0	100	0	0	0	100	0	0	0
Vancomycin	100	0	0	0	100	0	0	0	100	0	0	0

Abbreviations: S, susceptible; R, resistant; I, intermediate; ND, not determined.