Detection and Molecular Characterization of Escherichia coli CTX-M-15 and Klebsiella pneumoniae SHV-12 β-Lactamases from Bovine Mastitis Isolates in the United Kingdom

Dorina Timofte; Iuliana E. Maciuca; Nicholas J. Evans; Helen Williams; Andrew Wattret; Jenny C. Fick; Nicola J. Williams

doi:10.1128/AAC.00752-13

DOI: 10.1128/AAC.00752-13

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FIG 1
Schematic representations of environments surrounding bla_CTX-M-15 in common human isolates (a to c) and bovine mastitis isolate 26 reported here (d). Where known, elements are qualified as partial or complete (due to primer locations, in some cases elements cannot be classified as either partial or complete).

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TABLE 1

Antimicrobial susceptibility profiles of bovine mastitis E. coli and Klebsiella pneumoniae subsp. pneumoniae isolates and selected transconjugants^{^a}

Antimicrobial	MIC (μg/ml)^{^b}
	Parental isolates					Conjugants
	25(2053)	26(2104A)	27(2104B)	28(2104C)	32(2188)	26C(2104A)	28C(2104C)	32C(2188)
AMP	32	32	32	32	32	32	4	32
CFZ	32	32	32	32	32	32	4	32
FEP	2	4	8	4	8	8	2	8
CTX	4	32	32	16	64	32	0.12	32
CTX-CLA	0.25	0.06	0.5	0.5	0.25	4	0.06	4
FOX	128	2	128	128	2	128	16	128
CPD	64	64	64	64	64	64	1	64
CAZ	64	64	256	128	64	8	2	8
CAZ-CLA	0.5	0.06	0.5	0.5	0.25	2	0.25	2
CRO	16	64	64	32	128	64	0.5	64
CEF	32	32	32	32	32	32	NM	32
CIP	0.5	0.5	0.5	0.5	0.5	4	0.5	NM
GEN	32	32	16	16	32	16	2	16
IPM	0.25	0.25	0.25	0.25	0.25	0.25	0.25	0.25
MEM	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
PIP-TZB	2	2	128	8	2	2	2	2

↵a Abbreviations: AMP, ampicillin; CFZ, cefazolin; FEP, cefepime; CTX, cefotaxime; CTX-CLA, cefotaxime-clavulanic acid; FOX, cefoxitin; CPD, cefpodoxime; CAZ, ceftazidime; CAZ-CLA, ceftazidime-clavulanic acid; CRO, ceftriaxone; CEF, cephalothin; CIP, ciprofloxacin; GEN, gentamicin; IPM, imipenem; MEM, meropenem; PIP-TZB, piperacillin-tazobactam; NM, not measured.
↵b Bold represents resistance by CLSI interpretation rules.

TABLE 2

Characteristics of β-lactamase and ESBL genes in two E. coli and three Klebsiella pneumoniae subsp. pneumoniae clinical mastitis isolates

Isolate^{^a}	ESBL/fluoroquinolone genes in the isolates				Presence of replicon type:						ST by MLST	Phylogenetic group
Isolate^{^a}	bla_CTX-M	bla_SHV	bla_TEM	bla_QnrS	B/O	P1	K/B	FIB	I1	F	ST by MLST	Phylogenetic group
25 (K. pneumoniae)		SHV-12	TEM-1	+	−	−	+	−	−
26 (E. coli)	CTX-M-15		TEM-1	−	+	−	−	+	+	+	ST88	A
27(K. pneumoniae)		SHV-12	TEM-1	+	−	−	+	−	−	−
28 (K. pneumoniae)		SHV-12	TEM-1	+	−	−	+	−	−	−
32 (E. coli)	CTX-M-15		TEM-1	−	+	−	−	+	+	+		A
26C	CTX-M-15		TEM-1		−	+	−	−	+	−
28C					−	+	−	−	−	−
32C	CTX-M-15		TEM-1		−	+	−	−	+	−
K-12					−	+	−	−	−	−

↵a 25, 26, 27, 28, and 32 correspond to 25(2053), 26(2104A), 27(2104B), 28(2104C), and 32(2188), respectively. Isolates 25, 26, 27, 28, and 32 are original isolates; isolates 26C, 28C, and 32C are transconjugants; and K-12 is the E. coli recipient strain.