Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carriage and pattern of antibiotic resistance among sheep farmers from Southern Italy

Figures & data

Table 1 Characteristics of workers (N=275)

	N (%)
Demographics^a
Sex
Male	227 (82.6)
Female	48 (17.4)
Age (years)
≤45	142 (51.6)
>45	133 (48.4)
Marital status
Married/cohabitees	192 (70.1)
Other	82 (29.9)
Education level (years of schooling)
<8	256 (93.4)
≥8	18 (6.6)
Nationality
Italian	249 (90.5)
Other	26 (9.5)
Working activity^a
Contact with other livestock
Yes	198 (72.3)
No	76 (27.7)
Time employed in the sheep sector (years)
≤25	154 (56)
>25	121 (44)
Time spent on farm (hours/week)
≤40	98 (35.6)
>40	177 (64.4)
Days on a week spent on farm
≤4	26 (9.5)
>4	248 (90.5)
Hours in a day spent on farm
<9	146 (53.3)
≥9	128 (46.7)
Type of work in the farm^a
Feeding
Yes	229 (83.6)
No	45 (16.4)
Milking sheep
Yes	221 (80.7)
No	53 (19.3)
Giving birth assistance to sheep
Yes	158 (57.7)
No	116 (42.3)
Sheep shearing
Yes	181 (66.1)
No	93 (33.9)
Sheepfold cleaning
Yes	221 (80.7)
No	53 (19.3)
Biosafety practices^a
Personal protective equipment (PPE) use while working with sheep
Rubber boots
Yes	217 (79.2)
No	57 (20.8)
Rubber gloves
Yes	108 (39.4)
No	166 (60.6)
Disposable gloves
Yes	75 (27.4)
No	199 (72.6)
Hand-washing after PPE use
Yes	207 (76.4)
No	64 (23.6)
Home-washing working clothes
Yes	252 (92)
No	22 (8)
Frequency washing work clothes
More than once a month	10 (3.6)
More than once a week	137 (50)
Daily	127 (46.4)
General health^a
Skin problems in the last six months
Yes	34 (12.4)
No	240 (87.6)
Use of antibiotics in the last year
Yes	62 (22.6)
No	212 (77.4)
Access to health facilities in the last year^a
General practice
Yes	95 (34.7)
No	179 (65.3)
Hospitalization
Yes	20 (7.3)
No	254 (92.7)

Notes: ^aTotal may not always sum to “N” because of missing data.

Table 2 Prevalence of antibiotic resistance among the 95 Staphylococcus aureus isolates

Antibiotic classes	N (%)
Macrolides
Erythromycin	33 (34.7)
Tetracycline
Tetracycline	33 (34.7)
Streptogramines
Quinupristin-Dalfopristin	27 (28.4)
Lincosamides
Clindamycin	21 (22.1)
Oxazolidinones
Linezolid	21 (22.1)
Rifamycins
Rifampicin	19 (20)
Aminoglycosides
Gentamicin	8 (8.4)
Fluoroquinolones
Ciprofloxacin	8 (8.4)
Mupirocin	5 (5.3)
β-lactams
Cefoxitin	3 (3.2)
Oxacillin	3 (3.2)
Sulphonamides
Sulfamethoxazole/trimethoprim	1 (1.1)

Figure 1 Distribution of antibiotic resistance patterns of the 3 MRSA strains.

Notes: *Blackened cells indicate non-susceptibility and grey cells indicate susceptibility to the antibiotic. All MRSA isolates were susceptible to CIP, CLI, GEN, LNZ, SXT, RIF.

Abbreviations: CIP, ciprofloxacin; CLI, clindamycin; ERY, erythromycin; GEN, gentamicin; LNZ, linezolid; MUP, mupirocin; SXT, trimethoprim-sulfamethoxazole; QDA, quinupristin-dalfopristin; RIF, rifampicin; TET, tetracycline; CEF, cefoxitin; OX, oxacillin.

Table 3 Cross-resistance of Staphylococcus aureus isolates

Antimicrobials tested	n^a	% Resistance to:
		CIP	CLI	ERY	GEN	LNZ	MUP	SXT	QDA	RIF	TET	CEF	OX
CIP	8	-	50	62.5	25	50	0	0	37.5	62.5	50	0	0
CLI	21	19.1	-	66.7	14.3	57.1	0	0	47.6	38.1	52.4	0	0
ERY	33	15.2	42.4	-	18.2	36.4	6.1	0	39.4	27.3	60.6	6.1	6.1
GEN	8	25	37.5	75	-	25	0	12.5	37.5	25	50	0	0
LNZ	21	19.1	57.1	57.1	9.5	-	4.8	0	38.1	33.3	47.6	0	0
MUP	5	0	0	40	0	20	-	0	80	0	40	40	40
SXT	1	0	0	0	100	0	0	-	100	0	100	0	0
QDA	27	11.1	37	48.2	11.1	29.6	14.8	3.7	-	29.6	48.2	7.4	7.4
RIF	19	26.3	42.1	47.4	10.5	36.8	0	0	42.1	-	31.6	0	0
TET	33	12.1	33.3	60.6	12.1	30.3	6.1	3	39.4	18.2	-	6.1	6.1
CEF	3	0	0	66.7	0	0	66.7	0	66.7	0	66.7	-	100
OX	3	0	0	66.7	0	0	66.7	0	66.7	0	66.7	100	-

Notes: ^aNumber of resistant strains.

Abbreviations: CIP, ciprofloxacin; CLI, clindamycin; ERY, erythromycin; GEN, gentamicin; LNZ, linezolid; MUP, mupirocin; SXT, trimethoprim-sulfamethoxazole; QDA, quinupristin-dalfopristin; RIF, rifampicin; TET, tetracycline; CEF, cefoxitin; OX, oxacillin.

Figure 2 Minimum spanning tree of the Staphylococcus aureus isolates typed by Multiple-locus variable number of tandem repeat analysis (MLVA).

Notes: *These isolates were methicillin-sensitive S. aureus (MSSA).

Abbreviations: LA, livestock associated; MT, MLVA type; MC, MLVA complex.

Data availability

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.