Background
Methods
GBS culture, isolation and identification
Molecular confirmation of isolates
Sensitivity testing using Vitek
Plant material
Preparation of plant extracts
Gas chromatography-mass spectrometry (GC-MS) analysis
Preparation of plant extracts for antimicrobial activity
Agar well diffusion
Minimum inhibitory concentration (MIC) determination
Tube number | 1 | 2 | 3 | 4 |
---|---|---|---|---|
Concentration of essential oil (mg/ml) | 33.3 | 3.7 | 0.4 | 0.05 |
Concentration of leaf extract (mg/ml) | 0.1 | 0.02 | 0.004 | 0.0008 |
Results
Antibiotic | MIC (μg/mL) | Frequency (%) | ||
---|---|---|---|---|
Susceptible | Intermediate | Resistant | ||
Benzyl penicillin (P) | ≤ 0.12 | 154 (100.0) | 0 (0.0) | 0 (0.0) |
Ampicillin (Amp) | ≤ 0.25 | 154 (100.0) | 0 (0.0) | 0 (0.0) |
Cefotaxime (CTX) | ≤ 0.5 | 153 (99.4) | 0 (0.0) | 1 (0.6) |
Ceftriaxone (CRO) | ≤ 0.5 | 154 (100.0) | 0 (0.0) | 0 (0.0) |
Levofloxacin (Lev) | ≤ 2 | 154 (100.0) | 0 (0.0) | 0 (0.0) |
Erythromycin (E) | ≤ 0.25 | 138 (89.6) | 0 (0.0) | 16 (10.4) |
Clindamycin (CD) | ≤ 0.25 | 118 (76.6) | 0 (0.0) | 36 (23.4) |
Linezolid (Li) | ≤ 2 | 154 (100.0) | 0 (0.0) | 0 (0.0) |
Vancomycin (Va) | ≤ 1 | 154 (100.0) | 0 (0.0) | 0 (0.0) |
Tetracycline (T) | ≤ 2 | 6 (3.9) | 0 (0.0) | 148 (96.1) |
Cotrimoxazole (SXT) | ≤ 2 | 137 (89.0) | 0 (0.0) | 17 (11.0) |
Inducible clindamycin | 7 (4.5) |
S/N | Chemical constituents | Chemical formula | RT | Area % |
---|---|---|---|---|
1 | 2-Butenal, 2-ethenyl- | C6H8O | 3.255 | 1.56 |
2 | 2-Hexenal, (E)- | C6H10O | 3.292 | 2.95 |
3 | 1-Hexanol | C6H14O | 3.365 | 0.75 |
4 | Heptanal | C7H14O | 3.638 | 1.00 |
5 | (1S)-2,6,6-trimethylbicyclo[3.1.1] hept-2-ene | C10H16 | 3.975 | 1.89 |
6 | Pyridine, 3-ethenyl- | C7H7N | 4.204 | 2.21 |
7 | 2,4-Heptadienal, (E,E)- | C2H5CH | 4.412 | 1.58 |
8 | Octanal | C8H16O | 4.450 | 0.77 |
9 | alpha-Phellandrene | C10H16 | 4.530 | 1.72 |
10 | 4-Carene | C10H10 | 4.729 | 0.79 |
11 | 2-Octenal, (E)- | C8H14O | 4.908 | 0.50 |
12 | 1-Octanol | C8H18O | 4.972 | 1.87 |
13 | Pyridine, 5-ethenyl-2-methyl- | C8H9N | 5.198 | 0.88 |
14 | Nonanal | C9H18O | 5.271 | 10.57 |
15 | 1,6-heptadiene,2,5,5-trimethyl | C10H18 | 5.674 | 0.73 |
16 | Acetaldehyde, (3,3dimethylcyclohexylidene),(E) | C10H18O | 5.720 | 1.07 |
17 | 1-Methylpentyl cyclopropane | C9H18 | 5.772 | 0.80 |
18 | Decanal | C10H20O | 6.059 | 2.23 |
19 | 3-Isopropylidene-5-methyl-hex-4-en-2-one | C10H16O | 6.278 | 0.99 |
20 | Octane, 1-iodo- | C8H17I | 6.347 | 0.57 |
21 | 2,6-Octadien-1-ol, 3,7-dimethyl-(Z)- | C10H18O | 6.418 | 0.39 |
22 | 2-Decenal, (E)- | C10H18O | 6.485 | 2.78 |
23 | 2,4-Decadienal | C10H16O | 6.724 | 0.76 |
24 | 4-tert-Butylcatechol, dimethyl ether | C12H18O2 | 6.809 | 4.63 |
25 | 9-Oxabicyclo [4.2.1] non-7-en-3-one | C8H12O | 6.892 | 1.80 |
26 | 1-Oxaspiro [4.5] dec-6-ene, 2,6,10,10-tetramethyl- | C13H22O | 6.995 | 1.10 |
27 | 2-Undecenal | C11H20O | 7.206 | 0.78 |
28 | cis-beta-Farnesene | C15H24 | 7.422 | 0.60 |
29 | 1-(3,6,6-trimethyl-1,6,7,7a-tetrahydrocyclopenta [c] pyran-1-yl) ethanone | C13H18 | 7.510 | 0.72 |
30 | 2-Buten-1-one,1-(2,6,6-trimethyl-1-cyclohexen-1-yl)- | C13H20O | 7.631 | 0.50 |
31 | Caryophyllene | C15H24 | 7.751 | 2.04 |
32 | 5,9-Undecadien-2-one, 6,10-dimethyl- | C13H22O | 7.798 | 2.91 |
33 | 1H-Inden-1-one, 2,4,5,6,7,7a-hexahydro-4,4,7a-trimethyl- | C12H18O | 7.931 | 0.46 |
34 | 1,4,7,-Cycloundecatriene, 1,5,9,9-tetramethyl-, Z,Z,Z- | C15H24 | 7.974 | 0.44 |
35 | trans-beta-Ionone | C13H20O | 8.093 | 2.39 |
36 | 21.xi-methyl-17-isocholest-16-en-3beta-ol | C27H46O | 8.150 | 0.47 |
37 | Naphthalene, 1,2,3,4,4a,5,6,8a-octahydro-4a,8-dimethyl-2- (1-methylethenyl)-,[2R-(2 alpha, 4a alpha, 8a beta)] | C15H24 | 8.232 | 0.69 |
38 | Naphthalene, 1,2,4a,5,6,8a-hexahydro-4,7-dimethyl-1-(1-methylethyl)- | C15H34 | 8.323 | 2.91 |
39 | 1,6,10-Dodecatrien-3-ol,3711,trimethyl-, [S-(Z)]- | C15H26O | 8.508 | 1.82 |
40 | Benzoic acid, nonadecyl ester | C26H44O2 | 8.631 | 0.79 |
41 | 1H_Cycloprop[e] azulen-7-ol, decahydro-1,1,7-trimethyl-4-methylene-,[1ar-(1aalpha, 4a alpha, 7 beta, 7a beta, 7b alpha)]- | C15H24O | 8.750 | 0.80 |
42 | Caryophyllene | C15H24O | 8.809 | 1.49 |
43 | 4,2,8-Ethanylylidene-2H-1-benzopyran, octahydro-4-methyl- | C14H22O | 8.923 | 0.55 |
44 | 1,4-Methano-1H-indene, octahydro-1,7a-dimethyl-4-(1-methylethenyl)-[1S-(1 alpha, 3a beta, 4 alpha, 7a beta)]- | C15H24 | 8.961 | 0.52 |
45 | Bicyclo[4.4.0]dec-1-ene, 2-isopropyl-5-methyl-9-methylene | C15H24 | 9.089 | 5.65 |
46 | Heptadecane | C17H36 | 9.250 | 0.39 |
47 | 7-epi-cis-sesquisabinene hydrate | C15H26O | 9.281 | 0.94 |
48 | 2,6,10-Dodecatrien-1-ol, 3,7,11,trimethyl | C15H26O | 9.424 | 0.46 |
49 | 2-Pentadecanone, 6,10,14-trimethyl | C18H36O | 10.058 | 1.66 |
50 | 1,2-Benzenedicarboxylic acid, bis(2-methylpropyl) ester | C16H22O4 | 10.235 | 0.72 |
51 | Eicosane | C20H42 | 10.312 | 0.47 |
52 | 2,6,10,14,18-Pentamethyl-2,6,10,14,18-eicosapentaene | C25H42 | 10.467 | 0.97 |
53 | Dibutyl phthalate | C16H22O4 | 10.713 | 0.43 |
54 | Eicosane | C20H42 | 10.810 | 0.42 |
55 | Isopropyl palmitate | C19H38O2 | 10.930 | 0.29 |
56 | Heptasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11,13,13-tetradecamethyl- | C14H44 | 11.235 | 0.09 |
57 | Octadecane | C18H38 | 11.286 | 1.03 |
58 | 2-Myristynoyl-glycinamide | C16H31BrN2O2 | 11.336 | 0.77 |
59 | Phytol | C20H40O | 11.388 | 6.40 |
60 | 1H-Indole-2-carboxylic acid, 6-(4-ethoxyphenyl)-3-methyl-4-oxo-4,5,6,7-tetrahydro-, isopropyl ester | C21H25 | 11.741 | 0.55 |
61 | Nonadecane | C19H40 | 12.174 | 1.09 |
62 | Cyclotrisiloxane, hexamethyl | C6H18O3Si3 | 12.593 | 0.34 |
63 | Heptasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11,13,13-tetradecamethyl | C14H44O6Si7 | 12.994 | 0.98 |
64 | Octasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11,13,13,15,15-hexadecamethyl | C16H48O7Si8 | 13.779 | 1.81 |
65 | Tetrasiloxane, decamethyl- | C10H30O3Si4 | 14.201 | 0.37 |
66 | Silicic acid, diethyl bis (trimethylsilyl) ester | C10H28O4Si3 | 14.201 | 0.20 |
67 | Heneicosane | C21H44 | 14.659 | 3.37 |
68 | Tris (tert-butyldimethylsilyloxy) arsane | C18H45AsO3Si3 | 15.741 | 1.94 |
Discussion
Extract (Concentration) | Zone of inhibition on MH (Mean diameter) |
---|---|
Essential oil (300 mg/ml) | Present 25 mm |
Leaf extract (0.5 mg/ml) | Present 28 mm |
5 μg Ciprofloxacin (Positive control) | Present 35 mm |
10% DMSO (Negative control) | Not present 0 mm |
Concentration (mg/mL) | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0.05 | 0.4 | 3.7 | 33.3 | MIC | |||||||||
Isolates | A | B | C | A | B | C | A | B | C | A | B | C | Essential oils |
GBS in broth | + | + | – | + | + | – | + | + | – | – | + | – | 33.3 |
GBS on MH | + | + | – | + | + | – | + | + | – | – | + | – | 33.3 |
Concentration (mg/mL) | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0.0008 | 0.004 | 0.02 | 0.1 | MIC | |||||||||
Isolates | A | B | C | A | B | C | A | B | C | A | B | C | Leaf extracts |
GBS in broth | + | + | – | + | + | – | – | + | – | – | + | – | 0.02 |
GBS on MH | + | + | – | + | + | – | – | + | – | – | + | – | 0.02 |