Epidemiology of β-Lactamase-Producing Staphylococci and Gram Negative Bacteria as Cause of Clinical Bovine Mastitis in Tunisia

Table 1

Distribution of different isolated mastitis pathogens and their origins.

Farms	Number of milk Samples with mastitis	Period of sampling	Region Location	Number of positive milk samples with mastitis	Number of positive samples with Staphylococcus and /or Gram negative bacteria	Number of CNS	Number of S. aureus	Number of Gram negative bacteria	Coinfection of CNS and Gram negative bacteria
1	7	Autumn	North	4	5	1	1	3	1
2	11	Autumn	North	9	12	5	-	7	3
3	4	Winter	North	4	5	2	-	3	1
4	15	Winter	North	15	21	7	-	14	6
5	20	Winter	North	18	34	8	6	20	10
6	20		South	14	18	2	1	15	3
7	20		South	10	14	1	-	13	-
8	15	Spring	North	12	17	1	1	15	5
9	20		North	10	12	2	-	10	1
10	10		North	8	8	3	-	5	1
11	12		North	9	10	5	1	4	1
12	11	Spring	North	10	19	5	4	10	5
13	10		North	9	9	2	1	6	4
14	10	Spring	South	9	9	2	-	7	5
15	16		North	13	22	7	-	15	4
16	4	Summer	South	3	3	1	-	2	3
17	8		North	6	11	5	-	6	2
18	10	Summer	South	4	4	4	-	-	-
19	15		North	6	10	-	-	10	-
20	12		South	3	3	-	-	3	-
21	9		North	4	9	-	-	9	-
22	3	Summer	South	2	3	1	-	1	-
23	4		South	1	-	1	-	-	-
24	2		South	0	-	-	-	-	-
25	4		South	0	-	-	-	-	-
26	10	Autumn	North	9	3	3	-	-	-
27	5		North	0	-	-	-	-	-
28	3		South	0	-	-	-	-	-
29	6		South	0	-	-	-	-	-
30	4		South	0		-	-	-	-
Total	300			192	261	68	15	178	55

CNS= Coagulase-negative staphylococci; ESBL= Extended-spectrum beta-lactamases; S. aureus= Staphylococcus aureus; SARM=Methicillin resistant; S. aureus; MR-CNS= Methicillin resistant Staphylococcus coagulase negative.