Antibacterial and anti-biofilm effects of a polyherbal formula and its constituents against coagulase-negative and -positive staphylococci isolated from bovine mastitis

Figures & data

Table 1. Antibiotic susceptibility patterns of coagulase-positive staphylococci and coagulase-negative staphylococci isolated from bovine mastitis.

	Antibiotics^a (µg or unit/disc)
	AN	AM	E	GM	OX	P	RD	TE	VA
Tested isolates	(30)	(10)	(15)	(10)	(1)	(10)	(5)	(30)	(30)
Coagulase-positive staphylococci (CPS)
NPRC BCPS31	S	S	S	S	S	S	S	S	I
NPRC BCPS52	S	R	R	S	I	R	I	S	I
Coagulase-negative staphylococci (CNS)
NPRC BCNS18	S	S	S	S	S	R	S	S	I
NPRC BCNS19	S	R	S	S	I	R	S	S	I
NPRC BCNS20	S	S	I	S	S	R	S	S	I
NPRC BCNS21	S	S	I	S	S	S	S	S	I
NPRC BCNS22	S	S	I	S	S	S	S	S	I
NPRC BCNS27	S	R	I	S	S	R	S	S	R
NPRC BCNS28	S	R	I	S	S	R	S	S	I
NPRC BCNS29	S	R	I	S	I	R	S	S	R
NPRC BCNS40	S	S	I	S	S	R	S	S	I
NPRC BCNS43	S	R	I	S	S	R	I	S	I
NPRC BCNS44	S	R	I	S	I	R	S	S	R
NPRC BCNS45	S	S	I	S	S	S	S	S	R

^aAN = amikacin; AM = ampicillin; E = erythromycin; GM = gentamicin; OX = oxacillin; P = penicillin; RD = rifampicin; TE = tetracycline; VA = vancomycin.

Figure 1. Time kill assay of YSMP (a), A. catechu Linn. (b), C. longa Linn. (c), G. mangostana Linn. (d), curcumin (e), and α-Mangostin (f) against S. epidermidis ATCC 35984, coagulase-negative staphylococci NPRC BCNS018, and coagulase-positive staphylococci NPRC BCPS031. MHB containing 1% of DMSO was added as a positive control. MICs of YSMP, A. catechu, C. longa, G. mangostana, α-Mangostin, and curcumin against S. epidermidis ATCC 35984/BCNS018/BCPS031 were 7/15/31, 250/250/250, 125/250/250, 3/7/7, 1/10/10, and 31/250/250 µg/mL, respectively.

Table 2. MICs of ethanol extracts of YSMP, its herbal components, and active constituents against bovine mastitis-isolated coagulase-positive staphylococci (BCPS) and coagulase-negative staphylococci (BCNS).

	MICs (µg/mL)
	BCPS	BCNS	S. aureus	S. epidermidis
Tested agents	(n = 2)	(n = 12)	ATCC 25923	ATCC 35984
YSMP	32	15–32	4	7
A. catechu	250	250	250	250
C. longa	250	250	32	125
G. mangostana	7	7–15	3	3
O. sativa	>1000	>1000	>1000	>1000
α-Mangostin	10	10	1	10
Curcumin	>250	>250	32	125
Catechin	>250	>250	>250	>250

Table 3. Biofilm-forming ability of coagulase-positive staphylococci and coagulase-negative staphylococci isolates.

Tested isolates	Biofilm production (OD492nm ± SE)
Coagulase-negative staphylococci
NPRC BCNS018	0.739 ± 0.013
NPRC BCNS019	0.349 ± 0.002
NPRC BCNS020	0.143 ± 0.002
NPRC BCNS021	0.197 ± 0.007
NPRC BCNS022	0.178 ± 0.013
NPRC BCNS027	0.580 ± 0.009
NPRC BCPS028	0.374 ± 0.016
NPRC BCNS029	0.490 ± 0.005
NPRC BCNS040	0.188 ± 0.005
NPRC BCNS043	0.193 ± 0.014
NPRC BCNS044	0.660 ± 0.016
NPRC BCNS045	0.140 ± 0.008
Coagulase-positive staphylococci
NPRC BCPS031	0.953 ± 0.010
NPRC BCPS052	0.123 ± 0.015
S. epidermidis ATCC 35984	1.974 ± 0.003

Figure 2. Effect of different concentrations of YSMP (a), G. mangostana (b), and α-Mangostin (c) on the bacterial growth (white bars) and biofilm formation (black bars) of coagulase-positive staphylococci NPRC BCPS031. Note: Each bar indicates the percentage of the means of inhibition ± SE for three independent experiments performed in duplicate.

Figure 3. Scanning electron micrograph of BCNS 18 after treated with four MIC of YSMP (b), G. mangostana (c), A. catechu (d), C. longa (e), and alpha-mangostin (f). BCNS 18 (a) was growth in TSB used as a control. MICs of YSMP, G. mangostana, C. longa, A. catechu, and alpha-mangostin against BCNS 18 were 15, 7, 250, 250, and 10 µg/mL, respectively.

Figure 4. Transmission electron micrograph of BCNS 18 after treated with four MIC of YSMP (b), G. mangostana (c), A. catechu (d), C. longa (e), and alpha-mangostin (f). BCNS 18 (a) was growth in TSB used as a control. MICs of YSMP, G. mangostana, C. longa, A. catechu, and alpha-mangostin against BCNS 18 were 15, 7, 250, 250, and 10 µg/mL, respectively.