Genetic and Molecular Characterization of an Escherichia coli Plasmid Coding for Hydrogen Sulfide Production and Drug Resistance

Abstract

An H2S-producing variant of Escherichia coli (strain 142) isolated from a urinary tract infection was found to be resistant to high levels of tetracycline, ampicillin, streptomycin, and sulfonamide. The H2S trait segregated spontaneously at a frequency of 2.5 x 10-3. No segregation was observed for the drug resistance determinants. Neither ethidium bromide nor acridine orange affected the rate of segregation of the drug resistance determinants or the trait for H2S production. Antibiotic resistance and hydrogen sulfide production were conjugally transferred to E. coli K-12 recipients at a frequency of approximately 1i-5 per donor cell. Antibiotic resistance and hydrogen sulfide production were also transduced as a single unit with phage P1L4. Genetic data, based on the segregation of resistance determinants and the H2S trait among transconjugant and transductant classes, suggested the presence of two R plasmids. Plasmid DNA was isolated by cesium chloride-ethidium bromide centrifugation. Two plasmid species were detected by agarose gel electrophoresis of purified plasmid DNA, a large molecule of about 80 x 106 daltons (designated pSR12) and a small molecular species of approximately 5.5 x 106 daltons (designated pSR13). Transformation studies using purified plasmid DNA showed that the large pSR12 plasmid confers resistance to ampicillin, tetracycline, and streptomycin and also carries the gene(s) for H2S production. The small pSR13 plasmid confers resistance to streptomycin and sulfonamide.

CysB-dependent upregulation of the Salmonella Typhimurium cysJIH operon in response to antimicrobial compounds that induce oxidative stress

“…In this sense, several bacterial species could be able to use H 2 S as a cellular protector to increase resistance to ROS triggered by bactericidal antibiotics [11]. Enterobacteriaceae, including Salmonella genus, generates H 2 S in their natural environments mainly from thiosulfate [1,4]; however, the biochemistry and physiological roles of this gas in these species remains poorly described [11]. In this work, we propose a model in which H 2 S production against ROS depends on the sulfur source and the presence of the transcriptional regulator of the cysteine regulon, CysB, and the products of the cysJIH operon.…”

“…Accordingly, non-sulfur bacteria with mutations that suppress H 2 S production are highly sensitive to several antimicrobial compounds that exert their bactericidal effect via oxidative stress, including several b-lactam antibiotics [11,12]. The converse is also true since an Escherichia coli (E. coli) strain harboring a plasmid coding for proteins involved in H 2 S production, presented increased resistance to several antibiotics [4]. 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 In E. coli and other non-sulfur bacteria, the main mechanism to produce H 2 S is through b-mercaptopyruvate sulfurtransferase (sseA) using cysteine or thiosulfate as a sulfur source [6].…”

Unraveling the Physiological Complexities of Antibiotic Lethality

“…In bacteria that can produce both NO and H 2 S, the two gases were shown to act synergistically in protecting cells against killing by antibiotics (89). Interestingly, plasmid-borne elements enhancing basal H 2 S production were identified in multidrug-resistant patient isolates of E. coli nearly 40 years ago (90,91).…”

Genomic Characterization of New Variant of Hydrogen Sulfide (H2S)-Producing Escherichia coli with Multidrug Resistance Properties Carrying the mcr-1 Gene in China

“…The isolate was susceptible to carbapenems and cephalosporins ( Table 1). The study by Jones et al [3] and Harnett et al [9] demonstrated previously that an H 2 S-producing variant of Escherichia coli isolated from a urinary tract infection (UTI) was also found to be resistant to different clinically relevant antibiotics. A previous study by Bailey et al [1] reported the presence of dfrA12, sul3, tet(A), and cmlA1, including other AR genes in E. coli of healthy adults.…”

“…Specific biochemical examinations, including the hydrogen sulfide (H 2 S) test, are important for identification of the Enterobacteriaceae species. The production of H 2 S, however, is not a typical characteristic of E. coli, though the H 2 S-producing variants of E. coli have also been reported previously [2,3]. Bacteria can produce H 2 S through orthologous enzymes, and recent studies have implicated H 2 S as a significant signaling molecule by protecting the bacteria from antibiotic-induced damage [4].…”