Detection of OXA-48 Gene in Carbapenem-Resistant Escherichia coli and Klebsiella pneumoniae from Urine Samples

Figures & data

Table 1 Demographic Characteristics and Distribution of Bacterial Isolates in Urine Samples of Patients with Urinary Tract Infection (n=154)

Samples/Bacteria Identified/Characteristics	Culture Positive (Number)	Percentage (%)	p-Value
Urine (n=1013)	154	15.2
Gram-negative bacteria	141	91.5
Escherichia coli	97	62.9
Klebsiella pneumoniae	24	15.6
Klebsiella oxytoca	3	1.9
Citrobacter spp.	3	1.9
Proteus spp.	7	4.6
Pseudomonas spp.	4	2.6
Acinetobacter spp.	2	1.3
Serratia spp.	1	0.7
Gram-positive bacteria	13	8.5
Staphylococcus aureus	12	7.8
Enterococcus faecalis	1	0.7
Age group (years)
0–15 (n=150)	18	11.7	0.5
16–45 (n=475)	78	50.6
>45 (n=388)	58	37.7
Gender
Male (n=290)	35	22.7	0.1
Female (n=723)	119	77.3

Table 2 Antimicrobial Susceptibility Patterns of the Isolated E. coli and K. pneumoniae

Mode of Action	Antimicrobial Category	Antibiotics	E. coli (n=97)		K. pneumoniae (n=24)
			Sensitive	Resistant	Sensitive	Resistant
			N (%)	N (%)	N (%)	N (%)
Cell wall synthesis inhibitors	Aminopenicillin	Ampicillin (10 µg)	32 (33)	66 (67)	0 (0)	24 (100)
	Extended-spectrum cephalosporins	Ceftriaxone (30 µg)	48 (49.5)	49 (50.5)	5 (20.8)	19 (79.2)
		Cefixime (5 µg)	48 (49.5)	49 (50.5)	4 (16.7)	20 (83.3)
	Carbapenems	Imipenem (10 µg)	94 (96.9)	3 (3.1)	8 (33.3)	16 (66.7)
		Meropenem (10 µg)	93 (95.9)	4 (4.1)	8 (33.3)	16 (66.7)
Protein synthesis inhibitors	Aminoglycosides	Amikacin (30 µg)	90 (92.8)	7 (7.2)	12 (50)	12 (50)
Nucleic acid synthesis inhibitors	Quinolones	Nalidixic acid (30 µg)	27 (27.8)	70 (72.2)	11 (45.8	13 (54.2)
	Fluoroquinolones	Ciprofloxacin (5 µg)	46 (47.4)	51 (52.6)	12 (50)	12 (50)
		Norfloxacin (10 µg)	43 (44.3)	54 (55.7)	10 (41.7	14 (58.3)
	Nitrofurans	Nitrofurantoin (300 µg)	93 (95.9)	4 (4.2)	10 (41.7)	14 (58.3)
Folate pathway inhibitors	Trimethoprim and sulfamethoxazole	Cotrimoxazole (25 µg)	57 (58.8)	40 (41.2)	8 (33.3)	16 (66.7)

Figure 1 MDR in E. coli and K. pneumoniae.

Table 3 Prevalence of Multidrug Resistance (MDR), Carbapenem Resistance and OXA-48 in E. coli and K. pneumoniae

Characteristic	MDR	Carbapenem Resistance*	Modified Hodge Test	OXA-48
	N (%)	N (%)	N (%)	N (%)
Bacterial isolates
E. coli (n=97)	52 (70.3)	3 (27.3)	2 (28.6)	1 (33.3)
Klebsiella pneumoniae (n=24)	22 (29.7)	8 (72.7)	5 (72.4)	2 (66.7)
p-Value	<0.001	<0.001	0	0.15
Gender
Male	16 (21.6)	2 (18.2)	1 (16.7)	1 (33.3)
Female	58 (78.4)	9 (81.8)	6 (83.7)	2 (66.7)
p-Value	0.21	1	0.88	0.45
Age group (years)
0–15	4 (5.4)	0	0	0
16–45	39 (52.7)	7 (63.6)	4 (51.1)	2 (66.7)
>45	31 (41.9)	4 (36.4)	3 (49. 9)	1 (33.3)
p-Value	0.64	0.68	0.87	0.91

Note: *Phenotypically both imipenem and meropenem resistant.

Figure 2 Phenotypic detection of carbapenemase production by the modified Hodge test (MHT). 1: Negative control; 2, 3, 4: MHT-positive test isolates showing cloverleaf-like indentation due to carbapenemase production.

Figure 3 Antibiotic resistance profile of carbapenem-resistant E. coli and K. pneumoniae.

Figure 4 Agarose gel electrophoresis showing PCR-amplified OXA-48 gene (281 bp). Lane 1: 100 bp DNA ladder (Thermo Scientific); lane 2: positive control; lane 3: negative control; lanes 4–6: test plasmids positive for OXA-48 gene.