Bacteriological Profiles, Antimicrobial Susceptibility Patterns, and Associated Factors in Patients Undergoing Orthopedic Surgery with Suspicion of Surgical Site Infection at Arba Minch General Hospital in Southern Ethiopia

Figures & data

Table 1 Socio-Demographic Characteristics of Patients with Suspected Orthopedic Surgical Site Infection at Arba Minch General Hospital

Variables	Categories	Frequency (n)	Percentage (%)
Gender	Male	165	67.3
	Female	80	32.7
Age (years)	≤ 18	36	14.7
	19–38	110	44.9
	39–58	68	27.8
	59–78	31	12.7
Residence	Urban	106	43.3
	Rural	139	56.7
Educational status	Illiterate	8	3.3
	Primary	85	34.7
	Secondary	124	50.6
	Diploma & above	28	11.4
Occupation	Farmer	48	19.6
	House wife	19	7.8
	Merchant	52	26.9
	Student	66	21.2
	Employee	33	13.5
	Driver	27	11.0

Figure 1 Frequency of Bacterial Isolates from Infection Suspected Orthopedic Surgical Wounds at Arba Minch General Hospital.

Table 2 Association of Socio-Demographic Factors with Orthopedic Surgical Site Infection at Arba Minch General Hospital

Variables	Category	Culture Result		COR (95% CI)	AOR (95% CI)	P-value
		Positive (%)	Negative (%)
Sex	Male	45 (62.5)	120 (69.4)	0.736 (0.414–1.310)	0.682 (0.341–1.364)	0.279
	Female	27 (37.5)	53 (30.6)	1	1
Age	≥18	12 (16.7)	24 (13.9)	1.437 (0.497–4.157)	1.689 (0.460–6.198)	0.429
	19–38	32 (44.4)	78 (45.1)	1.179 (0.478–2.912)	1.606 (0.530–4.868)	0.403
	39–58	20 (27.8)	48 (27.7)	1.198 (0.459–3.125)	1.750 (0.539–5.679)	0.351
	59–78	8 (11.1)	23 (13.3)	1	1
Education	Illiterate	1 (1.4)	7 (4.0)	2.597 (0.303–22.276)
	Primary	23 (31.9)	62 (35.8)	3.212 (0.382–27.008)
	Secondary	39 (54.2)	85 (49.1)	3.316 (0.353–31.158)
	College & above	9 (12.5)	19 (11.0)	1
Residence	Urban	34 (47.2)	72 (41.6)	1	1
	Rural	38 (52.8)	101 (58.4)	1.255 (0.722–2.181)	0.664 (0.341–1.293)	0.228
Occupation	Farmer	10 (13.9)	38 (22.0)	1	1
	Housewife	6 (8.3)	13 (7.5)	1.754 (0.532–5.777)		0.356
	Student	19 (26.4)	47 (27.2)	1.536 (0.639–3.693)		0.337
	Merchant	16 (22.2)	36 (20.8)	1.689 (0.678–4.205)		0.260
	Employee	13 (18.1)	20 (11.6)	2.470 (0.921–6.623)		0.072
	Driver	8 (11.1)	19 (11.0)	1.600 (0.543–4.714)		0.394

Abbreviations: COR, crude odds ratio; AOR, adjusted odds ratio; CL, confidence interval.

Table 3 Association of Clinical and Behavioral Factors with Orthopedic Surgical Site Infections at Arba Minch General Hospital

Variables	Category	Culture-Result		COR (95% CI)	AOR (95% CI)	P-value
		Positive (%)	Negative (%)
Patient type	Admitted	61 (27.9%)	158 (72.1%)	0.526 (0.229–1.210)
	Follow up	11 (42.3%)	15 (57.7%)	1
Site of fracture	Upper extremity	17 (31.5%)	37 (68.5%)	0.613 (0.184–2.043)
	Lower Extremity	49 (27.7%)	128 (72.3%)	0.510 (0.168–1.547)
	Other	6 (42.9%)	8 (57.1%)	1
Nature of Surgery	Emergency	48 (26.8%)	131 (73.2%)	0.641 (0.352–1.169)
	Elective	24 (36.4%)	42 (63.6%)	1
Prophylaxis use before 30 mint of surgery	Yes	70 (29.3%)	169 (70.7%)	0.828 (0.148–4.627)
	No	2 (33.3%)	4 (66.7%)	1
Type of surgery	External fixation	45 (52.3%)	41 (47.7%)	5.122 (1.373–19.112)	4.761 (1.108–20.457)	0.036
	Open Reduction and Internal fixation	18 (17.3%)	86 (82.7%)	0.977 (0.254–3.754)	0.959 (0.228–4.376)	0.955
	Fusion	4 (18.2%)	18 (81.8%)	1.037 (0.199–5.410)	1.319 (0.221–7.881)	0.761
	Amputation	1 (14.3%)	6 (85.7%)	0.778 (0.067–9.076)	1.420 (0.105–19.203)	0.792
	Hemiarthroplasty	1 (11.1%)	8 (88.9%)	0.583 (0.052–6.587)	0.361 (0.027–4.861)	0.443
	Repair	3 (17.6%)	14 (82.4%)	1
Use of implant	Yes	61 (33.3%)	122 (66.7%)	2.318 (1.128–4.765)	3.470 (1.460–8.246)	0.005
	No	11 (17.7%)	51 (82.3%)	1	1
Length of time for surgery	<2hrs	46 (24.9%)	139 (75.1%)	1	1
	2–4hrs	26 (43.3%)	34 (56.7%)	2.311 (1.256–4.252)	3.225 (1.545–6.731)	0.002
Post-operative hospitalization	<7days	38 (21.0%)	143 (79.0%)	1
	≥7days	34 (53.1%)	30 (46.9%)	4.265 (2.323–7.829)	4.099 (2.026–8.293)	0.001
Wound type	Class I	9 (14.3%)	54 (85.7%)	1	1
	Class II	30 (27.8%)	78 (72.2%)	2.308 (1.015–5.249)	1.390 (0.527–3.666)	0.506
	Class III A	12 (42.9%)	16 (57.1%)	4.500 (1.609–12.588)	2.090 (0.645–6.773)	0.219
	Class III B	11 (44.0%)	14 (56.0%)	4.714 (1.635–13.594)	2.490 (0.711–8.720)	0.154
	Class III C	10 (47.6%)	11 (52.4%)	5.455 (1.798–16.545)	2.738 (0.740–10.131)	0.131
Comorbidity*	Yes	5 (33.3%)	10 (66.7%)	2.507 (0.703–8.942)
	No	67 (29.1%)	163 (70.9%)	1
Habit of Smoking	Yes	7 (9.7%)	26 (15.0%)	0.609 (0.251–1.476)
	No	65 (90.3%)	147 (85.0%)	1

Notes: *Human Immunodeficiency Virus (HIV) (n=4), Diabetic Mellitus (DM) (n=5), Hepatitis B virus (HBV) (n=3), Hypertension (n=3).

Abbreviations: COR, crude odds ratio; AOR, adjusted odds ratio; CL, confidence interval.

Table 4 Antimicrobial-Resistant Pattern of Gram-Positive Bacterial Isolates from Infection Suspected Orthopedic Surgical Wounds at Arba Minch General Hospital

Drugs	Pattern	S. aureus (n=19)	CoNS (n=10)	E. faecium (n=3)	Total (n=32)
		No (%)	No (%)	No (%)	No (%)
PEN	S	3(15.8)	2(20)	0(0)	5(15.6)
	I	1(5.3)	2(20)	0(0)	3(9.4)
	R	15(78.9)	6(60)	3(100)	24(75)
CXT	S	8(42.1)	6(60)	NA	14(43.8)
	I	0(0)	0(0)	NA	0(0)
	R	11(57.9)	4(40)	NA	15(46.9)
GEN	S	8(42.1)	6(60)	NA	14(43.8)
	I	1(5.3)	0(0)	NA	1(3.1)
	R	10(52.6)	4(40)	NA	14(43.8)
ERY	S	6(31.6)	5(50)	1(33.3)	12(37.5)
	I	2(10.5)	1(10)	0(0)	3(9.4)
	R	11(57.9)	4(40)	2(66.7)	17(53.1)
TET	S	7(36.8)	4(40)	0(0)	11(34.4)
	I	3(15.8)	2(20)	2(66.7)	7(21.9)
	R	9(47.3)	4(40)	1(33.3)	14(43.8)
DOX	S	8(42.1)	5(50)	1(33.3)	14(43.8)
	I	2(10.5)	1(10)	1(33.3)	4(12.5)
	R	9(47.3)	4(40)	1(33.3)	14(43.8)
CLD	S	6(31.6)	5(50)	NA	11(34.4)
	I	3(15.8)	1(10)	NA	4(12.5)
	R	10(52.6)	4(40)	NA	14(43.8)
COT	S	5(26.3)	6(60)	NA	11(34.4)
	I	2(10.5)	0(0)	NA	2(6.3)
	R	12(63.2)	4(40)	NA	16(50)
VAN	S	NA	NA	2(66.7)	2(6.3)
	I	NA	NA	0(0)	0(0)
	R	NA	NA	1(33.3)	1(3.1)
CHL	S	8(42.1)	6(60)	2(66.7)	16(50)
	I	3(15.8)	1(10)	0(0)	4(12.5)
	R	8(42.1)	3(30)	1(33.3)	12(37.5)

Abbreviations: PEN, Penicillin; CXT, Cefoxitin; GEN, Gentamicin; ERY, Erythromycin; TET, Tetracycline; DOX, Doxycycline; CLD, Clindamycin; COT, Cotrimoxazole; VAN, Vancomycin; CHL, Chloramphenicol; NA, not applicable based on CLSI 2020 guideline recommendation; S, sensitive; I, intermediate; R, resistant; CoNS, Coagulase Negative Staphylococci; spp, species.

Table 5 Antimicrobial Resistant Pattern of Gram-Negative Bacterial Isolates from Infection Suspected Orthopedic Surgical Wounds at Arba Minch General Hospital

Drugs	Pattern	K. pneumoniae (n=13)	E. coli (n=7)	P. aeruginosa (n=10)	Citrobacter spp. (n=4)	Entrobacter spp. (n=2)	A. baumannii (n=6)	Proteus spp. (n=2)	Total (n=44)
		No (%)	No (%)	No (%)	No (%)	No (%)	No (%)	No (%)	No (%)
AMP	S	3(23.1)	2(28.6)	NA	1(25)	1(50)	NA	0(0)	7(15.9)
	I	1(7.7)	1(14.3)	NA	0(0)	0(0)	NA	0(0)	2(4.5)
	R	9(69.2)	4(57.1)	NA	3(75)	1(50)	NA	2(100)	19(43.2)
PIP	S	NA	NA	6(60)	NA	NA	3(50)	NA	9(20.5)
	I	NA	NA	1(10)	NA	NA	0(0)	NA	1(2.3)
	R	NA	NA	3(30)	NA	NA	3(50)	NA	6(13.6)
AUG	S	7(53.8)	4(57.1)	NA	3(75)	2(100)	NA	2(100)	18(41)
	I	1(7.7)	1(14.3)	NA	0(0)	0(0)	NA	0(0)	2(4.5)
	R	5(38.5)	2(28.6)	NA	1(25)	0(0)	NA	0(0)	8(18.2)
CFP	S	2(15.4)	1(14.3)	2(20)	1(25)	0(0)	2(33.3)	0(0)	8(18.2)
	I	2(15.4)	1(14.3)	1(10)	0(0)	1(50)	0(0)	2(100)	7(15.9)
	R	9(69.2)	5(71.4)	7(70)	3(75)	1(50)	4(66.7)	0(0)	29(65.9)
CXT	S	4(30.8)	3(42.9)	NA	2(50)	1(50)	NA	2(100)	12(27.3)
	I	0(0)	0(0)	NA	0(0)	0(0)	NA	0(0)	0(0)
	R	9(69.2)	4(57.1)	NA	2(50)	1(50)	NA	0(0)	16(36.4)
CTR	S	3(23.1)	2(28.6)	NA	1(25)	0(0)	2(33.3)	1(50)	9(20.5)
	I	1(7.7)	1(14.3)	NA	1(25)	1(50)	1(16.7)	0(0)	5(11.4)
	R	9(69.2)	4(57.1)	NA	2(50)	1(50)	3(50)	1(50)	20(45.5)
CRX	S	2(15.4)	1(14.3)	NA	1(25)	1(50)	NA	0(0)	5(11.4)
	I	2(15.4)	1(14.3)	NA	0(0)	0(0)	NA	1(50)	4(9.1)
	R	9(69.2)	5(71.4)	NA	3(75)	1(50)	NA	1(50)	19(43.2)
CFZ	S	NA	NA	3(30)	NA	NA	2(33.3)	NA	5(11.4)
	I	NA	NA	0(0)	NA	NA	0(0)	NA	0(0)
	R	NA	NA	7(70)	NA	NA	4(66.7)	NA	11(25)
GEN	S	5(38.5)	3(42.9)	4(40)	2(50)	2(100)	3(50)	2(100)	21(47.7)
	I	2(15.4)	1(14.3)	1(10)	1(25)	0(0)	0(0)	0(0)	5(11.4)
	R	6(46.2)	3(42.9)	5(50)	1(25)	0(0)	3(50)	0(0)	18(40.9)
MER	S	7(53.8)	4(57.1)	6(60)	3(75)	2(100)	4(66.7)	2(100)	28(63.6)
	I	1(7.7)	1(14.3)	1(10)	0(0)	0(0)	0(0)	0(0)	3(6.8)
	R	5(38.5)	2(28.6)	3(30)	1(25)	0(0)	2(33.3)	0(0)	13(29.5)
TET	S	4(30.8)	2(28.6)	NA	1(25)	1(50)	2(33.3)	1(50)	11(25)
	I	2(15.4)	1(14.3)	NA	1(25)	0(0)	0(0)	0(0)	4(9.1)
	R	7(53.8)	4(57.1)	NA	2(50)	1(50)	4(66.7)	1(50)	19(43.2)
DOX	S	5(38.5)	3(42.9)	NA	2(50)	1(50)	3(50)	1(50)	15(34.1)
	I	1(7.7)	1(14.3)	NA	0(0)	0(0)	0(0)	0(0)	2(4.5)
	R	7(53.8)	3(42.9)	NA	2(50)	1(50)	3(50)	1(50)	17(38.6)
CPR	S	2(15.4)	2(28.6)	3(30)	1(25)	0(0)	2(33.3)	1(50)	11(25)
	I	2(15.4)	1(14.3)	0(0)	0(0)	1(50)	0(0)	0(0)	4(9.1)
	R	9(69.2)	4(57.1)	7(70)	3(75)	1(50)	4(66.7)	1(50)	29(65.9)
COT	S	4(30.8)	3(42.9)	NA	2(50)	1(50)	2(33.3)	1(50)	13(29.5)
	I	1(7.7)	0(0)	NA	1(25)	0(0)	1(16.7)	0(0)	3(6.8)
	R	8(61.5)	4(57.1)	NA	1(25)	1(50)	3(50)	1(50)	18(40.9)
CHL	S	7(53.8)	4(57.1)	NA	3(75)	2(100)	NA	2(100)	18(40.9)
	I	1(7.7)	1(14.3)	NA	0(0)	0(0)	NA	0(0)	2(4.5)
	R	5(38.5)	2(28.6)	NA	1(25)	0(0)	NA	0(0)	8(18.2)

Abbreviations: AM, Ampicillin; PIP, Piperacillin; AUG, Augmentin; CFP, Cefepime; CXT, Cefoxitin; CTR, Ceftriaxone; CRX, Cefuroxime; CFZ, Ceftazidime; GEN, Gentamicin; MER, Meropenem; TET, Tetracycline; DOX, Doxycycline; CPR, Ciprofloxacin; COT, Cotrimoxazole; CHL, Chloramphenicol; NA, not applicable as per CLSI 2020 guideline; S, sensitive; I, intermediate; R, resistant; spp, species.

Table 6 Multi-Drug Resistance Pattern of Bacterial Isolates from Infection Suspected Orthopedic Surgical Wounds at Arba Minch General Hospital

Bacterial Isolates	Antibiogram Pattern (%)
	R1	R2	R3	≥R4	Total
S. aureus (n=19)	4(21.1)	5(26.3)	3(15.8)	1(5.3)	13(68.4)
CoNS (n=10)	3(30)	2(20)	1(10)	0(0)	6(60)
E. faecium (n=3)	0(0)	1(33.3)	0(0)	1(33.3)	2(66.7)
K. pneumoniae (n=13)	3(23.1)	4(30.8)	1(7.7)	1(7.7)	9(69.2)
P. aeruginosa (n=10)	3(30)	3(30)	1(10)	0(0)	7(70)
E. coli (n=7)	1(14.3)	1(14.3)	2(28.6)	1(14.3)	5(71.4)
A. baumannii (n=6)	1(16.7)	1(16.7)	2(33.3)	0(0)	4(66.7)
Citrobacter spp. (n = 4)	1(25)	0(0)	1(25)	1(25)	3(75)
Entrobacter spp. (n=2)	0(0)	1(50)	0(0)	0(0)	1(50)
Proteus spp. (n=2)	1(50)	0(0)	0(0)	0(0)	1(50)
Total MDR isolates (n=76)	17(22.4)	18(23.7)	11(14.5)	5(6.6)	51(67.1)

Notes: R1, R2, R3, and R4: Resistant to at least one antibiotic from; three classes, four classes, five classes and six and more classes of antibiotics, respectively.

Abbreviations: MDR, multidrug resistant; CoNS, Coagulase Negative Staphylococci; spp, species.

Table 7 Biofilm Formation of Bacterial Isolates from Infection Suspected Orthopedic Surgical Wounds at Arba Minch General Hospital

Bacterial Isolates	Frequency (n=76)	Biofilm Formation
	No (%)	SBF (%)	MBF (%)	WBF (%)	NBF (%)
S. aureus	19 (25)	7 (36.8)	3 (15.9)	3 (15.9)	6 (31.6)
CoNS	10 (13.2)	2 (20)	3 (30)	1 (10)	4 (40)
E. faecium	3 (3.9)	0 (0)	2 (66.7)	0 (0)	1 (33.3)
K. pneumoniae	13 (17.1)	4 (30.8)	2 (15.4)	2 (15.4)	5 (38.5)
P. aeruginosa	10 (13.2)	3 (30)	2 (20)	1 (10)	4 (40)
E. coli	7 (9.2)	2 (28.6)	1 (14.3)	0 (0)	4 (57.1)
A. baumannii	6 (7.9)	2 (33.3)	1 (16.7)	0 (0)	3 (50)
Citrobacter spp.	4 (5.3)	0 (0)	1 (25)	1 (25)	2 (50)
Entrobacter spp.	2 (2.6)	1 (50)	0 (0)	0 (0)	1 (50)
Proteus spp.	2 (2.6)	0 (0)	0 (0)	0 (0)	2 (100)
Total	76 (100)	21 (27.6)	15 (19.7)	8 (10.5)	23 (30.3)

Abbreviations: CoNS, Coagulase Negative Staphylococci; SBF, Strong Biofilm Former; MBF, Moderate Biofilm Former; WBF, Weak Biofilm Former; NBF, Non-Biofilm Former; spp, species.