Results
Distribution of bacteria in different clinical specimens
The distribution of bacterial isolates in various clinical specimens is displayed (see Table 2). Each organism's total number, together with the number and percentage of isolates from each type of specimen, are shown (see Table 2).
Table 2: Distribution of bacteria in different clinical specimens
Specimen type
|
S.aureus
134
|
CoNS
71
|
E.coli
179
|
P.aeruginosa
197
|
S.pyogenes
53
|
K.pneumoniae
106
|
S.typhi
79
|
Proteus spp
41
|
Total
860 (%)
|
Urine
|
28 (3.26)
|
19 (2.21)
|
22 (2.56)
|
27 (3.14)
|
15(1.74)
|
22(2.56)
|
0(0)
|
6(0.70)
|
139(16.16)
|
Nasal Swab
|
10 (1.60)
|
10 (1.60)
|
12 (1.40)
|
2 (0.23)
|
1(0.12)
|
3(0.35)
|
0(0)
|
0(0)
|
38(4.44)
|
U/S
|
4 (0.47)
|
1 (0.12)
|
16 (1.86)
|
5 (0.58)
|
2(0.23)
|
11(1.28)
|
0(0)
|
4(0.47)
|
43(5.00)
|
HVS
|
19 (2.21)
|
7 (0.81)
|
17(1.98)
|
17 (1.98)
|
6(0.70)
|
17(1.98)
|
0(0)
|
6(0.70)
|
89(10.35)
|
Catheter(urine)
|
9 (1.04)
|
8 (0.93)
|
6 (0.70)
|
42 (4.88)
|
3(0.35)
|
6(0.70)
|
0(0)
|
1(0.12)
|
75(8.72)
|
Blood
|
20 (2.33)
|
2 (0.23)
|
7 (0.81)
|
7 (0.81)
|
10(1.60)
|
15(1.74)
|
20(2.33)
|
5(0.58)
|
86(10.00)
|
Eye Swab
|
12 (1.40)
|
6 (0.70)
|
7 (0.81)
|
7 (0.81)
|
5(0.58)
|
5(0.58)
|
0(0)
|
0(0)
|
42(4.88)
|
Stool
|
0 (0)
|
0 (0)
|
27(3.14)
|
0 (0)
|
0(0)
|
0(0)
|
59(6.86)
|
0(0)
|
86(10.00)
|
Sputum
|
14 (1.63)
|
3 (0.35)
|
19 (2.21)
|
10(1.60)
|
3(0.35)
|
10(1.60)
|
0(0)
|
10(1.60)
|
69(8.02)
|
Ear swab
|
6 (0.70)
|
3 (0.35)
|
5 (0.58)
|
29(3.37)
|
4(0.47)
|
15(1.74)
|
0(0)
|
8(0.93)
|
70(8.14)
|
Wound
|
12 (1.40)
|
12 (1.40)
|
14 (1.63)
|
51(5.93)
|
4(0.47)
|
2(0.23)
|
0(0)
|
1(0.12)
|
123(14.30
|
Total
|
134(15.58)
|
71(8.26)
|
179(20.12)
|
197(22.91)
|
53(6.16)
|
106(12.33)
|
79(9.18)
|
41(4.77)
|
860(100)
|
Isolated Bacterial Distribution by Patients in Various Hospital Wards
The distribution of isolated bacteria is depicted in accordance with samples taken from patients in various hospital wards (see Table 3). The number and percentage of the eight different bacterial species from eleven different specimens collected from patients in nine wards are displayed (see Table 3).
Table 3: Isolated Bacterial Distribution by Patients in Several Hospital Wards
Bacterial
Isolate
|
Total
No(%)
|
MMW
No(%)
|
FMW
No(%)
|
AW
No(%)
|
FSW
No(%)
|
MSW
No(%)
|
OPD
No(%)
|
CW
No(%)
|
EW
No(%)
|
PNW
No(%)
|
S. aureus
|
134(15.58)
|
31(3.60)
|
28(3.26)
|
7(0.81)
|
4(0.47)
|
11(1.28)
|
16(1.86)
|
19(2.21)
|
13(1.51)
|
5(0.58)
|
CoNS
|
71(8.26)
|
14(1.62)
|
12(1.40)
|
14(1.62)
|
12(1.40)
|
4(0.47)
|
4(0.47)
|
1(0.12)
|
8(0.93)
|
2(0.23)
|
E. coli
|
179(20.81)
|
29(3.37)
|
28(3.26)
|
11(1.28)
|
19(2.21)
|
18(2.09)
|
19(2.21)
|
27(3.14)
|
20(2.33)
|
8(0.93)
|
P. aeruginosa
|
197(20.91)
|
37(4.30)
|
37(4.30)
|
7(0.81)
|
8(0.93)
|
27(3.14)
|
32(3.72)
|
9(1.05)
|
20(2.33)
|
20(2.33)
|
S. Pyogenes
|
53(6.16)
|
15(1.74)
|
11(1.28)
|
1(0.12)
|
0(0.00)
|
10(1.16)
|
10(1.16)
|
1(0.12)
|
3(0.35)
|
2(0.23)
|
S. typhi
|
79(9.19)
|
17(1.98)
|
15(1.74)
|
1(0.12)
|
0(0.00)
|
14(1.63)
|
14(1.63)
|
2(0.23)
|
9(1.05)
|
7(0.81)
|
Proteus spp
|
41(4.76)
|
7(0.81)
|
8(0.93)
|
2(0.23)
|
2(0.23)
|
4(0.47)
|
7(0.81)
|
0(0.00)
|
4(0.47)
|
7(0.81)
|
K. pneumonia
|
106(12.33)
|
30(3.49)
|
23(2.67)
|
0(0.00)
|
0(0.00)
|
17(1.98)
|
22(2.56)
|
1(0.12)
|
11(1.28)
|
2(0.23)
|
Total
|
860(100)
|
180(20.99)
|
162(18.84)
|
43(5.00)
|
45(5.23)
|
105(12.21)
|
124(14.42)
|
60(6.98)
|
88(10.22)
|
53(6.16)
|
KEY: Male medical ward (MMW), Female medical ward(FMW), Male surgical ward(MSW), Female surgical ward (FSW), Antenatal ward (AW), Postnatal ward(PNW), children’s ward(CW), Emergency ward(EW), Outpatient department(OPD), cons= coagulase negative staphylococci, spp= species, no=number, %=percentage.
Distribution of MDR bacteria
Following the susceptibility testing, 42 (4.88%) out of the eight hundred and sixty (860) bacteria from different clinical specimens were multidrug-resistant (see Table 4).
Table 4: Distribution of multidrug-resistant bacteria
Name of bacteria
|
No. of Multidrug resistant bacteria
|
% of Organism with
MDR bacteria
|
NO. of Antibiotics resistant to bacteria
|
P. aeruginosa
|
14
|
33.33
|
6-7
|
S. aureus
|
14
|
33.33
|
6-7
|
E. coli
|
9
|
21.43
|
6-8
|
K. pneumonia
|
5
|
11.91
|
6-7
|
Total
|
42
|
100%
|
|
The multidrug resistance profile and multidrug resistance index of the bacteria
The bacterial multidrug resistance profile and multidrug resistance index are shown (see Table 5). The average MDRI was 0.6, while the lowest MDRI was 0.5. The peak MDRI (0.8) was exhibited by S. aureus.
Table 5: MDR profiles of Bacteria and their MDRI
S/No
|
Bacteria
|
MDR Profile
|
MDRI
|
1
|
S. aureus
|
LBC-P-ERY-AUG-CIP-CD-CRO
|
0.6
|
2
|
S. aureus
|
GX-CRO- ZEM-LBC – CIP – AZN – P
|
0.6
|
3
|
S. aureus
|
ZEM – CIP-CN-CD-P- OFX AUG – CN
|
0.6
|
4
|
S. aureus
|
CIP – AZN – CD-CN – P- LBC CRO – ERY
|
0.7
|
5
|
S. aureus
|
ZEM – CD- CIP – OFX – P – CN – LBC – CRO
|
0.7
|
6
|
S. aureus
|
ZEM-ERY – AZN- P – CIP – OFX
|
0.5
|
7
|
S. aureus
|
CN-CD-OFX – P- LBC – ERY- GX
|
0.6
|
8
|
S. aureus
|
LBC – CN – AZN –ERY CIP – P – OFX
|
0.6
|
9
|
E. coli
|
LBC – AZN – ERY-CD – CIP – P – OFX
|
0.6
|
10
|
E. coli
|
CIP – LBC – ERY – P – CD – OFX
|
0.5
|
11
|
E. coli
|
LBC – P – GX –CN-OFX- AZN ERY – CRO
|
0.7
|
12
|
E. coli
|
CRO – ERY – P- LBC – OFX – AZN – AUG - ZEM
|
0.7
|
13
|
E. coli
|
ZEM – LBC – CIP – CRO – P – CN
|
0.5
|
14
|
E. coli
|
AZN – LBC – ERY – P – CIP – CRO
|
0.5
|
15
|
E. coli
|
CD – CN – GX – P – CIP – CRO
|
0.5
|
16
|
E. coli
|
OFX – CD – CN – CRO – AZN AUG – LBC
|
0.6
|
17
|
E. coli
|
OFX – CD – CN – AZN – AUG – LBC
|
0.5
|
18
|
S. aureus
|
P – GX –CD – CN – AZN – OFX – AUG – CIP
|
0.7
|
19
|
S. aureus
|
CD – AZN – AUG – CRO – CIP – GX – LBC – ERY –P
|
0.8
|
20
|
S. aureus
|
GX –CD – CN –OFX – CIP – CRO – LBC- ERY
|
0.8
|
21
|
S. aureus
|
AZN – GX – CD – CN – CRO – CIP
|
0.5
|
22
|
K. pneumoniae
|
ZEM-LBC-CIP-ERY-CN-CD-GX-CRO
|
0.7
|
23
|
K. pneumonia
|
ERY-CRO-AZN-P-CIP-LBC-CD
|
0.6
|
24
|
K. pneumoniae
|
LBC-CN-P-CIP-OFX-CRO
|
0.5
|
25
|
K. pneumonia
|
CRO-CN-GX-CIP-OFX-P
|
0.5
|
26
|
K. pneumoniae
|
AZN-P-CIP-CN-GX-CRO
|
0.5
|
27
|
P. aeruginosa
|
AZN-P-CIP-CN-GX-CRO
|
0.5
|
28
|
P. aeruginosa
|
AZN – CRO – OFX – P – LBC – CIP
|
0.5
|
29
|
P. aeruginosa
|
ZEM – P – CIP – OFX – AZN – AUG
|
0.5
|
30
|
P. aeruginosa
|
P – CIP – OFX – CRO – LBC – CN – GX
|
0.6
|
31
|
P. aeruginosa
|
GX – ZEM – P – CIP – CN – CRO LBC
|
0.6
|
32
|
P. aeruginosa
|
ZEM – CRO – LBC – P – CIP – ERY
|
0.5
|
33
|
P. aeruginosa
|
CN – P – CIP – OFX – LBC – ERY
|
0.5
|
34
|
P. aeruginosa
|
CN – P – CIP – OFX – LBC
|
0.5
|
35
|
P. aeruginosa
|
AZN – CRO – GX – ZEM – CD – AUG
|
0.5
|
36
|
P. aeruginosa
|
P – CIP – AZN – ERY – AUG – OFX
|
0.5
|
37
|
P. aeruginosa
|
P – CIP – AZN – ERY – LBC – AUG
|
0.5
|
38
|
P. aeruginosa
|
LBC – AUG – CN – OFX – CD – AZN
|
0.5
|
39
|
P. aeruginosa
|
ZEM – LBC – CD– AUG – OFX – CN
|
0.5
|
40
|
P. aeruginosa
|
GX – CRO – CIP – LBC – ERY – CN- OFX
|
0.6
|
41
|
S. aureus
|
CRO – CIP – LBC – GX – P – AZN – CD
|
0.6
|
42
|
S. aureus
|
CN – CRO -CIP -LBC -GX – P – CD
|
0.6
|
|
|
|
|
|
|
|
Key: MDR= multidrug resistant, MDRI= multidrug resistant index, Piperacillin-Tazobactam=P, Cefixime = ZEM, Erythromycin = ERY, Augumentin = AUG, Cefotaxine = GX Levofloxacin = LBC, Azithromycin = AZN, Gentamicin=CN, Ceftriaxone = CRO, Cipfloxacin = CIP, Clindamycn = CD, Ofloxacin = OFX
Molecular weights of the extracted bacterial plasmids
The plasmid samples of the fifteen (15) selected multidrug-resistant organisms were subjected to electrophoresis. The plasmid samples on gel electrophoresis are shown (see Figure 1). Lane i is for the standards used, while the test bacterial plasmids occupy lanes ii-xvi. Bacterium on lane iii has a plasmid weight of 22.490kbp, while bacteria on lanes vi and vii have the same plasmid weight of 20.844kbp. The bacteria on lanes xii and xiv have a common plasmid weight of 161.435kbp, while the bacteria on lanes xiv, xv and xvi have a similar plasmid weight of 187.499kbp. Bacteria on lanes ii, iv, v, viii, ix, x and xi showed no plasmid band.
The molecular weight of plasmids, the bacteria, the specimen the bacteria were sourced from, and the wards where the patients who gave the samples were admitted to the hospital are shown (see Table 6).
Table 6: Molecular weight of the bacterial plasmids
Lane in gel
|
Molecular weight (kbp) Band 1
|
Bacteria
|
Sample
|
Ward
|
ii
|
55.847
|
S. aureus
|
U/S
|
OPD
|
iii
|
22.490
|
S. aureus
|
Urine(Catheter)
|
MMW
|
iv
|
55.847
|
S. aureus
|
Urine
|
MMW
|
v
|
55.847
|
P. aeruginosa
|
Wound
|
FSW
|
vi
|
20.844
|
P. aeruginosa
|
Wound
|
MSW
|
vii
|
20.844
|
P. aeruginosa
|
Wound
|
MSW
|
viii
|
55.847
|
P. aeruginosa
|
Wound
|
FSW
|
ix
|
55.847
|
P. aeruginosa
|
Urine(Catheter)
|
MSW
|
x
|
55.847
|
E. coli
|
Wound
|
MSW
|
xi
|
55.847
|
E. coli
|
Urine
|
OPD
|
xii
|
161.435
|
E. coli
|
Urine
|
MMW
|
xiii
|
161.435
|
K. pneumonia
|
Urine
|
MMW
|
xiv
|
187.499
|
K. pneumonia
|
HVS
|
FSW
|
xv
|
187.499
|
K. pneumonia
|
HVS
|
FSW
|
xvi
|
187.499
|
K. pneumonia
|
HVS
|
FSW
|
Key: Male medical ward (MMW), Female medical ward (FMW), Male surgical ward (MSW), Female surgical ward (FSW), Outpatient Department (OPD).
The drug-resistant pattern of the selected MDR bacteria before and after plasmid curing
The drug-resistant pattern of the selected MDR bacteria before and after plasmid curing is shown (see Table 7). The plasmids on lanes iii, vi, vii, xii, xiii, xiv, xv, and xvi conferred the bacteria resistant to the listed antibiotics were cured of the plasmid after treating them with 10% SDS, thereby making them susceptible to those antibiotics. However, the bacteria with plasmids on lanes ii, iv, v, viii, ix, x, and xi were resistant to the above-listed antibiotics and maintained their resistance totally or partially to the same drugs after curing.
Table 7: Drug-resistant pattern of some multidrug-resistant bacteria before and after
plasmid curing
Bacteria Lane
|
Resistant profile before curing
|
Resistant profile after curing
|
S. aureus ii
|
GX-CRO-ZEM-LBC-CIP-AZN-P
|
GX-ZEM-LBC-P
|
S. aureus iii
|
ZEM-CIP-CN-CD-P-OFX-AUG-GX
|
NIL
|
S. aureus iv
|
CIP-AZN-CD-CN-P-LBC-CRO-ERY
|
CIP-AZN-CD-CN-P-LBC-CRO-ERY
|
P.aeruginosa v
|
AZN-P-CIP-CN-GX-CRO
|
AZN-P-CIP-CN-GX-CRO
|
P.aeruginosa vi
|
AZN-CRO-OFX-P-LBC-CIP
|
NIL
|
P.aeruginosa vii
|
ZEM-P-CIP-OFX-AZN-AUG
|
NIL
|
P.aeruginosa viii
|
P-CIP-OFX-CRO-LBC-CN-GX
|
P-CIP-OFX-CRO-LBC-CN-GX
|
P.aeruginosa ix
|
GX-ZEM-P-CIP-CN-CRO-LBC
|
GX-ZEM-P-CIP-CN-CRO-LBC
|
E.coli x
|
LBC-AZN-ERY-CD-CIP-P-OFX
|
LBC-AZN-ERY-CD-CIP-P-OFX
|
E.coli xi
|
CIP-LBC-ERY-P-CD-OFX
|
ERY-P-CD-OFX
|
E.coli xii
|
LBC-P-GX-CN-OFX-AZN-ERY-CRO
|
NIL
|
K.pneumoniae xiii
|
REM-LBC-CIP-ERY-CN-CD-GX-CRO
|
NIL
|
K.pneumoniae xiv
|
ERY-CRO-AZN-P-CIP-EBC-CD
|
NIL
|
K.pneumoniae xv
|
LBC-CN-P-CIP-OFX-CRO
|
NIL
|
K.pneumoniae xvi
|
CRO-CN-GX-CIP-OFX-P
|
NIL
|
KEY: SDS= Sodium dodecyl Sulphate, NIL= N0 resistance drugs, Piperacillin-Tazobactam=P, Cefixime = ZEM, Erythromycin = ERY, Augmentin = AUG, Cefotaxine = GX Levofloxacin = LBC, Azithromycin = AZN, Gentamicin=CN, Ceftriaxone = CRO, Cipfloxacin = CIP, Clindamycin = CD, Ofloxacin = OFX
Discussion
Infectious pathogens' multidrug resistance is a serious risk and a barrier to finding the appropriate chemotherapy. Understanding the resistance pattern is therefore essential to fighting the battle against bacterial drug resistance. This research on plasmid profiling of multidrug-resistant bacteria from different clinical specimens was conducted at the Chukwuemeka Odumegwu Ojukwu University Teaching Hospital (COOUTH), Awka. Different isolated bacteria from various clinical samples were selected, and the multidrug-resistant ones were confirmed before bacterial plasmid extraction, analysis and curing using SDS.
In this investigation, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Coagulase Negative Staphyloccocus (CoNS), Pseudomonas aeruginosa, Salmonella typhi, and Proteus Spp were among the numerous bacteria recovered from the varied clinical samples (see Table 2). P. aeruginosa had the highest prevalence rate in the examined clinical samples (22.91%), followed by E. coli (20.81%), S. aureus(15.58%), K. pneumonia (12.33%), S. typhi (9.18%), CoNS (8.26%) and Proteus spp. (4.77%) (see Table 2). Some previous studies, [22, 23, 24], which isolated S. aureus, K. pneumoniae, E. coli, P. aeruginosa and Proteus Spp. had reported a similar trend. A study by Huai et al. [25] almost followed a similar pattern except for S. aureus which had higher occurrence than P. aeruginosa and E. coli. Also, a report showed that the most prevailing bacterial isolates from their study were E. coli and S. aureus [26]. It is common knowledge that S. aureus and E. coli can coexist as healthy skin flora, but they can also become contagious when there is a break in the skin due to a wound or surgery, or if the immune system is weak or suppressed [27, 28].
According to the distribution of bacteria isolates among the various specimens, the urine sample had the most isolates, totaling 139 (16.16%), followed by wounds (123 (14.30%)), HVS (89 (10.35%)), stool (86 (10.00%)), blood (86 (10.00%)), catheter (urine) (75 (8.72%)), ear swab (70 (8.14%)), sputum (69 (8.02%)), U/S (43 (5.00%)), eye swab(42 (4.88%)) and nasal swab (38 (4.44%)) [see Table 2]. This is in line with the findings of Amsalu et al. [29], who found that the frequency of bacteria in urine was 44.3%. According to Fahim's [30] analysis of data from another study conducted in Egypt, the majority of pathogens were discovered in blood cultures (44.84%), followed by urine (41.41%), and wound swabs (13.75%). The bacterial frequency seen in different samples in our study could be attributed to the relative sample sizes in response to the demands for clinical studies. The surroundings, patient conditions, personal hygiene, the number of patients involved in each study, the source of the sample, and laboratory techniques, among others, can all have an effect.
Further look into the result [see Table 2] reveals the frequency of specific isolates from the various samples. S. aureus had the highest number of 28 (3.26%) in the urine sample. This was closely followed by P. aeruginosa ( 27 (3.14%)). Both K. pneumoniae and E. coli contained 22 (2.56%) isolates. This is consistent with the findings of Ekwealor et al. [31] who showed that S. aureus was the most common urine pathogen to be isolated in Awka, followed by E. coli. They continued by pointing out that earlier research had connected the rise in Staphylococcus urinary tract infections (UTIs) to an increase in the use of instruments like bladder catheterization. The reported high percentage of Staphylococcus differed from other earlier studies that were published and identified E. coli to be the main pathogen of the urinary tract [31]. This is in contrast to the findings of Amsalu et al. [29], who said that between January 2012 and December 2014 in Southern Ethiopia, the most common isolate from urine was E. coli (42.9%), followed by K. pneumoniae (12.7%), and S. aureus (12.7%). However, the difference in geographic location and period of investigation may be the reason for this departure from the findings of our study.
Other urinary tract samples had the followings [see Table 2]; HVS had S. aureus (19 (2.21%)), and 17 (1.98%) isolates of P. aeruginosa and E. coli each. Urethral swab had E. coli (16 (1.86%)), K. pneumoniae (11(1.28%)) and S. aureus (4 (0.47%)). P. aeruginosa (42, 4.88%), Staphylococcus aureus (9, 1.04%), and Escherichia coli (6, 0.70%) were all found in the urine collected via the catheter. These findings are consistent with those of Kolawole et al. [32], who said that E. coli, S. aureus, Proteus species, K. pneumonia, and P. aeruginosa are the most prevalent pathogenic organisms of urinary tract infections (UTI).
P. aeruginosa was the most common isolate among bacteria isolated from urinary tract samples. The least number of isolates were S. aureus, E. coli, K. pneumoniae, CoNS, and Proteus Spp. [see Table 2]. This is consistent with the findings of Mohammed et al. [33], who indicated that the predominant bacteria they isolated for their study were E. coli and S. aureus. S. aureus and E. coli were the two bacteria that were most commonly isolated, according to Amin et al. [34], however E. coli has consistently been the isolate that causes urinary tract infections in similar research. Also, this is in accordance with the findings of Demilie et al. [26], who observed that E. coli, which accounted for 90% of the cases in their study, is the main etiologic agent causing urinary tract infections. According to Rachid et al. [35], the urinary tract (42.9%) was the site of infection most frequently impacted by Staphylococcus, followed by E. coli and K. pneumoiae. The highest frequency of all isolates in this investigation, however, was found in the urinary tract samples (Urine 16.16%, HVS 10.35%, U/S 5.00%, and urine from catheter 8.72%). The report of Unegbu et al. [36] stating that urinary tract infection has the greatest prevalence of 36.33% is directly related to this. The high occurrence of urinary tract infections may be caused by unsanitary hospital and restroom conditions.
P. aeruginosa (51 (5.93%)) was the most prevalent isolate in the wound sample out of a total of 123 (14.30%) isolates [see Table 2]. Then came CoNS (12 (1.40%), S. aureus (12 (1.40%), and E. coli (14 [4.7%]). This is consistent with the findings of Motayo et al. [37], who suggested that an endogenous infection source may be to blame for the high prevalence of P. aeruginosa and S. aureus infections. Environmental contamination may also be the cause of these organisms' infections. S. aureus may easily enter wounds due to the breakdown of the natural skin barrier. According to Basu et al. [38], the relatively high number of P. aeruginosa isolates is indicative of a high incidence of nosocomial infections, particularly in hospitalised patients. This raises the issue of the necessity of strict infection control procedures and good hygiene, such as frequent hand washing and the sterilization of wound care providers' tools. According to the research by Ehiaghe et al. [39], surgical wounds exposed to numerous pervasive environmental infections, such as unsterile surfaces, water, and dirt, had the largest number of clinical isolates of P. aeruginosa in their wound swabs. In contrast, Shittu et al. [40] observed that S. aureus was the most common etiologic agent of wound infection in numerous healthcare institutions in their research area after microbiological examination of wound sample.
From blood samples, 86 bacteria in all (10.00%) were recovered. There are several of them, including S. aureus, E. coli, P. aeruginosa, S. typhi, CoNS, S. pyogenes, and K. pneunomiae. As a consequence, S. aureus and S. typhi had the highest number of isolates (20 each, or 2.33%), followed by K. pneumoniae (15, or 1.74%), and S. pyogenes (10, or 1.60%), according to the results [see Table 2]. This is closely similar to the study by Mehta et al. [41] which revealed that the most frequent organisms linked to septicemia include S. aureus, E. coli, P. aeruginosa, S. typhi, CoNS, and K. pneunomiae. On the other hand, Alam et al. [42] revealed that the main septicemia-causing organisms were Gram-positive pathogens, Coagulase-negative staphylococci, S. aureus, and Gram-negative S. typhi. This is supported by a research by Falagas et al. [43], which found that coagulase-negative staphylococci are the most common cause of septicemia. However, S. typhi was identified as the main pathogen by Onile et al. [44]. According to Taiwo et al. [45], this variation may be due to the selection of drug-resistant bacteria isolates that were better adapted for survival, which has changed the etiology of blood stream infection.
Our research showed that only two bacteria were recovered from 86 (10.00%) isolates found in stool samples (see Table 2). These are E. coli (27) and S. typhi (59, 6.86%). This was somewhat supported by the findings by Amsalu et al. [29], who isolated only S. typhi (41.70%) and Shigella spp. (58.39%).These bacteria are primary intestinal commensals present in endothermic animals [46].
Nasal swab samples produced 38 (4.44%) bacterial isolates [see Table 2]. These comprised P. aeruginosa (2 (0.23%), S. aureus (10 (1.60%), K. pneumoniae (3 (0.35%), and E. coli (12 (1.40%). This is consistent with the findings of the article by Amsalu et al. [29], which demonstrated the isolation of Proteus Spp. (8.3%), K. pneumonia (58.3%), P. aeruginosa (8.3%), and E. coli (16.7%).
Our findings on the relationship between the different hospital wards and the bacterial is shown [see Table 3]. According to the results, the male medical ward (MMW) had the most isolates, 180 (20.99%), followed by the female medical ward (FMW) and the outpatients department (OPD), which had 162 (18.84%) and 124 (14.42%), respectively, isolates. The Antenatal Ward (AW) has the fewest isolats, with 43 (5.00%). In general, the surgical wards (FSW and MSW) had a total of 150 (17.44%) isolates, which was followed by the medical wards (MMW and FMW), which had the highest number of isolates (342 (39.77%)). These results are consistent with those of Rachid et al. [35], who said that the medical and surgical wards, with 392 (32.8%) and 379 (31.7%) infections, respectively, had the largest number of infections. But according to Lizioli et al. [47], the rate of surgical site infections appears to be higher than what is generally reported around the world.
All the isolated bacteria were subjected to the effects of different antibiotics. A total of 42 (4.88%) out of the 860 bacteria from different clinical specimens were multidrug (6-8 antibiotics) resistant (see Table 4). P. aeruginosa and S. aureus, with fourteen (14 (33.33%)) each, had the highest number of drug resistance, to 6-7 of the twelve (12) antibiotics used. Also, nine (9 (21.43%)) Escherichia coli were resistant to 6-8 of all the drugs used, while five (5 (11.90%)) K. pneumoniae were resistant to 6-7 antibiotics used. In comparison to the results of this investigation, a prior study on the bacterial profile and multidrug (> 4 drugs) resistance pattern of bacterial isolates among probable cases of septicemia in Ethiopia showed a multidrug resistance rate of 74.2% [48]. Similarly, in another study in Ghana and Nigeria [49,50], P. aeruginosa, E. coli and K. pneumonia were reported to be among the Gram-negative multidrug-resistant bacterial pathogens. Different studies have also reported P. aeruginosa, S. aureus, E. coli and K. pneumonia the most frequently reported multidrug resistant isolates [51,52]. The environment's inappropriate and unregulated use of antibiotics as well as inadequate infection control practices may be to blame for the multi-drug resistant bacteria. It has been stated that in order to stop the establishment of new resistant strains, it is imperative to analyse resistant isolates using susceptibility testing given the overuse of antibiotics in hospitals and the continued growth in antibiotic resistance [53].It is crucial to remember that resistance patterns may differ from region to region due to genetic mutation brought on by inappropriately given antibiotics.
The results of multidrug resistance profile and multidrug resistance index of the bacteria has been shown (see Table 5). The average MDRI was 0.6, while the lowest MDRI was 0.5. The peak MDRI (0.8) was exhibited by S. aureus. The prevalence of bacterial resistance in a particular community has reportedly been revealed by MDRI [50]. A study recorded Streptococcus spp. as the only isolate that gave MDRI below 0.20 while other isolates were above 0.20 [31]. However, our findings revealed that all 42 bacteria had a high MDRI index value above 0.2. When the MDRI index is greater than 0.2, it indicates that the organisms were isolated in an environment where antibiotics are misused. Additionally, a significant portion of the bacterial isolates have been exposed to multiple antibiotics and have subsequently developed resistance to these antibiotics [31, 54].The results indicate that this is the case in this study.
The results of the plasmids analyses are shown (see Figure 1). As observed, some of the multidrug-resistant bacteria harbour varied molecular weights plasmids while others harbour no plasmid, indicating that the latter's resistance was chromosomally borne. This agrees with the report that some of the multidrug-resistant isolates had plasmid band during electrophoresis while others did not, despite that they were all multidrug-resistant [55]. Plasmid mediated bacterial resistance has been widely reported [56, 57, 58, 59]. Our study indicates that some of the multidrug resistant isolates harbored resistance plasmids which probably must have been acquired.
A comparison of plasmid sizes and numbers (see Table 6) shows that some of the bacteria have plasmid bands of the same number and sizes, suggesting that they are likely of the same origin, most probably in the same community or close to the hospital where this study was carried out. As they can be produced and selected by horizontal transfer, it has been proposed that multidrug-resistant plasmids could be acquired by susceptible bacteria during antibiotic treatment [4, 60]. The existence of drug resistance plasmids may also result from selective pressure brought on by the increased use and abuse of antimicrobial drugs, according to studies [61, 62]. However, other investigations suggested that, in addition to environmental factors, the development of resistance can be caused by chromosomal mutations or plasmids that can be transferred from one strain of an organism to another across species [63, 64]. As a result, the gene responsible for antibiotic resistance may be found on both chromosomal and plasmid DNA, or both. This has been supported by a report that some multidrug-resistant isolates without plasmid bands, following gel electrophoresis, indicated that their resistance might be chromosomal mediated since some remained resistant after curing using 10% sodium dodecyl sulphate [65]. Additionally, it has been noted that in some bacteria, the absence of a plasmid may not be sufficient proof to demonstrate that the trait is plasmid-encoded [66,70] due to the fact that numerous plasmids are capable of integrating into the bacterial host genome.
A crucial technique for investigating the numerous properties of plasmids is plasmid curing. By acting on the bacterial membrane and creating pores there, SDS is mostly used to cure plasmids. From our findings, some bacteria were cured totally by the treatment with 10% SDS, while others were either partially cured or unaffected by the curing agent (see Table 7). Eight bacteria on lanes iii, vi, vii, xii to xvi were cured totally, two bacteria on lanes ii and xi were partially cured, while five others on lanes iv, v, viii, ix, and x were not affected by the curing agent as they remained resistant to those drugs after treatment. Given the high frequency of SDS in curing resistant bacteria, our study is in accordance to previous studies [67, 68]. The efficacy of curative agents against multidrug resistant bacterial isolates cannot be predicted because there are no standard methods that are relevant to all plasmids [66]. While some curing agents damage and disrupt the cells in a non-specific manner, others act specifically [69]. It is understood that no plasmid curing agent is capable of removing all plasmids from various bacteria [70]. Given that SDS is the only curing agent employed in our investigation, this may help to explain the incomplete or no curing reported in some bacteria. In the future, it will be required to test a wide range of curing techniques before finding one that works well for each bacterium [66]. SDS has been identified as the most effective curing agent for P. aeruginosa's resistant plasmid [67]. Resistant plasmid-containing cells may be more sensitive to SDS because of the plasmid-specific pili on the cell surface [66]. Through the pili necessary for aggregation, SDS can interfere with bacterial cell-to-cell transmission [71, 72]. By preventing the plasmid's conjugational transfer, this may limit the spread of antibiotic-resistant plasmid in the environment.
Furthermore, it should be highlighted that even while many plasmids are refractory or difficult to cure, this does not always suggest that the resistant trait is not encoded by the plasmid [66]. However, investigations have indicated that plasmid curing can improve antibiotic efficacy because of the greater susceptibility with post-plasmid curing compared to pre-plasmid curing [73, 74]. Given that plasmid-mediated resistance to many antimicrobial drugs has been shown [see Table 7], this claim is consistent with the findings of our study.