Virulent nontyphoidal Salmonella producing CTX-M and CMY-2 β-lactamases from livestock, food and human infection, Brazil

Figures & data

Table 1. Epidemiologic and molecular characterization of ESBL/pAmpC-producing non-typhoidal Salmonella strains recovered from livestock, food and human infection, Brazil (2008–2015).

Strain	Serovar	Source	Year/State^a	Resistance pattern^b	MLST ST (CC)	ESBL/ pAmpC	Plasmid transfer^c	Plasmid size (~kb)	PBRT^d	pMLST ST (CC)	Virulence genes	Galleria mellonella mortality (%)^e
SAL785	S. Schwarzengrund	Drag swab	2008/PR	AMP, SAM, CRO, CTF, CIP, ENO, TET	96 (33)	CTX-M-2	T	291	UT	–	aceK, invA, slyA, sopB	100
SAL769	S. Agona	Turkey meat	2008/SC	AMP, SAM, CRO, CTF, CIP, ENO, TET, SXT	13 (54)	CTX-M-2	C	97	IncI1	113	aceK, invA, slyA, sopB	100
SAL58370	S. Typhimurium	Chicken meat	2010/MS	AMP, SAM, CRO, CTF, TET, SXT	19 (1)	CTX-M-2	T	240	UT	–	aceK, h-1i, invA, slyA, sopB	100
SAL65505	S. Minnesota	Chicken meat	2010/MS	AMP, SAM, CRO, CTF, TET, SXT	3088	CMY-2	C	97	IncI1	12 (12)	aceK, invA, slyA, sopB	100
SAL77088	S. Minnesota	Chicken meat	2010/PR	AMP, CRO, CTF	548 (77)	CTX-M-8	C	97	IncI1	113	aceK, invA, slyA, sopB	100
SAL68375	S. Heidelberg	Turkey meat	2010/MG	AMP, CRO, CTF	19 (1)	CTX-M-8	C	97	IncI1	113	aceK, invA, slyA, sopB	90
SAL70447	S. Minnesota	Chicken meat	2010/PR	AMP, CRO, CTF, TET	548 (77)	CTX-M-8	T	97	IncI1	113	aceK, invA, slyA, sopB	100
SAL219	S. enterica subsp enterica 4,5,12:i:-	Swine feces	2012/MG	AMP, SAM, CRO, CTF, CHL, CIP, ENO, TET, SXT	19 (1)	CTX-M-8	NT	340/97	IncP/UT	–	aceK, h-1i, invA, slyA, sopB	100
SAL14	S. Muenchen	Human infection	2013/SP	AMP, SAM, CRO, CTF, CIP, ENO, TET	112 (8)	CTX-M-2	NT	194	IncP	–	aceK, invA, slyA, sopB	100
SAL64	S. Infantis	Chicken meat	2015/SC	AMP, CRO, CTF, CHL, TET, SXT	32 (31)	CTX-M-8	C	97	IncI1	113	aceK, invA, slyA, sopB	100

Notes.

^a PR, Paraná (South Brazil); SC, Santa Catarina (South); MS, Mato Grosso do Sul (Central-west); MG, Minas Gerais (South-east); SP, São Paulo (South-east).

^b AMP, ampicillin; SAM, ampicillin-sulbactam; CRO, ceftriaxone; CTF, ceftiofur; CHL, chloramphenicol; CIP, ciprofloxacin; ENO, enrofloxacin; TET, tetracycline; SXT, trimethoprim/sulphamethoxazole.

^c T, transformation; C, conjugation; NT, not transferred.

^d UT, untyped.

^e G. mellonella larvae were inoculated with 10⁵ CFU of NTS. SAL58370 and SAL219 caused 100% of mortality at 7 h post-infection; SAL70447 caused 100% of mortality at 8 h post-infection; SAL785, SAL769, SAL65505, SAL77088, SAL14, and SAL64 caused 100% of mortality at 21 h post-infection; SAL68375 caused 90% of mortality at 7 h post-infection; S. Typhimurium ATCC 14028 caused 40% and 60% of mortality at 7 h and 48 h post-infection, respectively; no mortality was observed in G. mellonella groups infected with ESBL-negative S. Typhimurium IAL 1431 and E. coli ATCC 25922 strains.

Figure 1. Kaplan-Meier survival curves of Galleria mellonella infected with 10⁵ CFU/larva of NTS strains. Cephalosporin-sensitive (ESBL-negative) S. Typhimurium ATCC 14028 and S. Typhimurium IAL 1431 were utilized as control strains. (A) Strain SAL58370, which had 100% mortality at 7 h post-infection. (B) Strain SAL70447, which had 100% mortality at 8 h post-infection. (C) Strain SAL14, which had 100% mortality at 21 h post-infection. (D) Strain SAL68375, which had 90% mortality at 7 h post-infection. Injection with the wild-type strains resulted in significantly higher mortality rate compared to injection with the control strains (P<0.05, log rank test).