scholarly journals Metagenomics of Antimicrobial and Heavy Metal Resistance in the Cecal Microbiome of Fattening Pigs Raised without Antibiotics

2021 ◽  
Vol 87 (8) ◽  
Author(s):  
Paiboon Tunsagool ◽  
Wuttichai Mhuantong ◽  
Sithichoke Tangphatsornruang ◽  
Nutthee Am-In ◽  
Rungtip Chuanchuen ◽  
...  

ABSTRACT This study aimed to assess the cecal microbiome, antimicrobial resistance (AMR), and heavy-metal resistance genes (MRGs) in fattening pigs raised under antibiotic-free (ABF) conditions compared with ordinary industrial pigs (control, C) using whole-genome shotgun sequencing. ABF pigs showed enrichment of Prevotella (33%) and Lactobacillus (13%), whereas Escherichia coli (40%), Fusobacterium, and Bacteroides (each at 4%) were notably observed in the C group. Distinct clusters of cecal microbiota of ABF and C pigs were revealed; however, microbiota of some C pigs (C1) appeared in the same cluster as ABF and were totally separated from the remaining C pigs (C2). For AMR genes, the most abundant genes, tet(Q) (35.7%) and mef(A) (12.7%), were markedly observed in the ABF group, whereas tet(Q) (26.2%) and tet(W) (10.4%) were prominently shown in the C group. tet(Q) was positively correlated with Prevotella in ABF and C1 samples. In the C2 group, the prominent tet(W) was positively correlated with Fusobacterium and Bacteroides. The pigs studied here have never received tetracycline, but pregnant sows received chlortetracycline once every 7 days before parturition. Chromosomal Cu and Zn resistance genes were also shown in both groups regardless of the received Cu and Zn feed additives. A higher abundance of multimetal resistance genes was observed in the C group (44%) than with the ABF group (41%). In conclusion, the microbiome clusters in some C pigs were similar to that in ABF pigs. High-abundance tetracycline resistance genes interrelated to major bacteria were observed in both ABF and C pigs. MRGs were also observed. IMPORTANCE AMR is an increasing problem in farm animals, and raising farm animals without antibiotics is one method that could solve this problem. Our study showed that only some tetracycline and macrolide resistance genes, tet(Q), tet(W), and mef(A), were markedly abundant in ABF and C groups. The tet(Q) and tet(W) genes interrelated to different predominant bacteria in each group, showing the potential role of major bacteria as reservoirs of AMR genes. In addition, chromosomal Cu and Zn resistance genes were also observed in both pig groups, independent of the use of Cu and Zn additives on both farms. The association of MRGs and AMR genotypes and phenotypes, together with the method to resensitize bacteria to antibiotics, should be studied further to unveil the cause of genes conferring high-level resistance and solve these problems.

2019 ◽  
Vol 8 (4) ◽  
Author(s):  
Yong-Joon Cho ◽  
Ahnna Cho ◽  
Soon Gyu Hong ◽  
Han-Gu Choi ◽  
Ok-Sun Kim

Arthrobacter oryzae TNBS02 was isolated from soil at Terra Nova Bay of Victoria Land, Antarctica. The genome consists of a chromosome with 4,248,670 bp which contains a total of 3,994 genes.


2017 ◽  
Vol 83 (20) ◽  
Author(s):  
Mingmei Lu ◽  
Shuo Jiao ◽  
Enting Gao ◽  
Xiuyong Song ◽  
Zhefei Li ◽  
...  

ABSTRACT The symbiosis of the highly metal-resistant Sinorhizobium meliloti CCNWSX0020 and Medicago lupulina has been considered an efficient tool for bioremediation of heavy metal-polluted soils. However, the metal resistance mechanisms of S. meliloti CCNWSX00200 have not been elucidated in detail. Here we employed a comparative transcriptome approach to analyze the defense mechanisms of S. meliloti CCNWSX00200 against Cu or Zn exposure. Six highly upregulated transcripts involved in Cu and Zn resistance were identified through deletion mutagenesis, including genes encoding a multicopper oxidase (CueO), an outer membrane protein (Omp), sulfite oxidoreductases (YedYZ), and three hypothetical proteins (a CusA-like protein, a FixH-like protein, and an unknown protein), and the corresponding mutant strains showed various degrees of sensitivity to multiple metals. The Cu-sensitive mutant (ΔcueO) and three mutants that were both Cu and Zn sensitive (ΔyedYZ, ΔcusA-like, and ΔfixH-like) were selected for further study of the effects of these metal resistance determinants on bioremediation. The results showed that inoculation with the ΔcueO mutant severely inhibited infection establishment and nodulation of M. lupulina under Cu stress, while inoculation with the ΔyedYZ and ΔfixH-like mutants decreased just the early infection frequency and nodulation under Cu and Zn stresses. In contrast, inoculation with the ΔcusA-like mutant almost led to loss of the symbiotic capacity of M. lupulina to even grow in uncontaminated soil. Moreover, the antioxidant enzyme activity and metal accumulation in roots of M. lupulina inoculated with all mutants were lower than those with the wild-type strain. These results suggest that heavy metal resistance determinants may promote bioremediation by directly or indirectly influencing formation of the rhizobium-legume symbiosis. IMPORTANCE Rhizobium-legume symbiosis has been promoted as an appropriate tool for bioremediation of heavy metal-contaminated soils. Considering the plant-growth-promoting traits and survival advantage of metal-resistant rhizobia in contaminated environments, more heavy metal-resistant rhizobia and genetically manipulated strains were investigated. In view of the genetic diversity of metal resistance determinants in rhizobia, their effects on phytoremediation by the rhizobium-legume symbiosis must be different and depend on their specific assigned functions. Our work provides a better understanding of the mechanism of heavy metal resistance determinants involved in the rhizobium-legume symbiosis, and in further studies, genetically modified rhizobia harboring effective heavy metal resistance determinants may be engineered for the practical application of rhizobium-legume symbiosis for bioremediation in metal-contaminated soils.


2016 ◽  
Vol 60 (8) ◽  
pp. 5006-5009 ◽  
Author(s):  
Hsiao-Jan Chen ◽  
Yu-Tzu Lin ◽  
Wei-Chun Hung ◽  
Jui-Chang Tsai ◽  
Po-Ren Hsueh ◽  
...  

ABSTRACTWe analyzed the staphylococcal cassette chromosomemec(SCCmec) types of 143 fusidic acid- and methicillin-resistantStaphylococcus epidermidisisolates. The most frequent SCCmectype was SCCmecIII/SCCHg(53%), followed by SCCmecIV (29%). Clonal spreading of SCCmecIII/SCCHgstrains contributed to the increased prevalence of SCCmecIII. A novel non-mecSCC structure, SCC7684, adjacent to SCCmecIII, which carries a newccrCallotype (ccrC3allele 1) and contains heavy metal resistance genes, was identified in 14 isolates.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ghulam Raza Mustafa ◽  
Ke Zhao ◽  
Xueping He ◽  
Shujuan Chen ◽  
Shuliang Liu ◽  
...  

Metals are widely used in animal feed for their growth-stimulating and antimicrobial effects, yet their use may potentially promote the proliferation of antibiotic resistance through co-selection. We studied the prevalence and associations of metal, antibiotic, and disinfectant resistances of 300 Salmonella Typhimurium isolates from pig meat, pig manure, chicken meat, poultry manure, and human stool from Sichuan, China. Seventy four percent of the 300 Salmonella Typhimurium isolates were considered resistant to Cu, almost 50% to Zn and Cr, over 25% to Mn and Cd, and almost 10% to Co. Most of the isolates carried at least one heavy metal resistance gene (HMRG). The Cr-Zn-Cd-resistance gene czcD was carried by 254 isolates and the Cu-resistance genes pcoR and pcoC by 196 and 179 isolates, respectively. Most of the isolates were resistant to at least one antibiotic and almost 80% were multidrug-resistant. The prevalence of resistance to six antibiotics was higher among the pig meat and manure isolates than among other isolates, and that of streptomycin and ampicillin were highest among the pig meat isolates and that of ciprofloxacin and ofloxacin among the pig manure isolates. From 55 to 79% of the isolates were considered resistant to disinfectants triclosan, trichloroisocyanuric acid, or benzalkonium chloride. The metal resistances and HMRGs were associated with resistance to antibiotics and disinfectants. Especially, Cu-resistance genes were associated with resistance to several antibiotics and disinfectants. The transfer of the Cr-Zn-Cd-resistance gene czcD, Cu-resistance gene pcoC, and Co-Ni-resistance gene cnrA into Escherichia coli and the increased Cu-resistance of the transconjugants implied that the resistance genes were located on conjugative plasmids. Thus, the excessive use of metals and disinfectants as feed additives and in animal care may have the potential to promote antibiotic resistance through co-selection and maintain and promote antibiotic resistance even in the absence of antibiotics.


2018 ◽  
Vol 62 (5) ◽  
pp. e02642-17 ◽  
Author(s):  
Qiu E. Yang ◽  
Siham Rajab Agouri ◽  
Jonathan Mark Tyrrell ◽  
Timothy Rutland Walsh

ABSTRACTThe occurrence of heavy metal resistance genes in multiresistantEnterobacteriaceaepossessingblaNDM-1orblaCTX-M-15genes was examined by PCR and pulsed-field gel electrophoresis with S1 nuclease. Compared with clinical susceptible isolates (10.0% to 30.0%), thepcoA,merA,silC, andarsAgenes occurred with higher frequencies inblaNDM-1-positive (48.8% to 71.8%) andblaCTX-M-15-positive (19.4% to 52.8%) isolates, and they were mostly located on plasmids. Given the high association of metal resistance genes with multidrug-resistantEnterobacteriaceae, increased vigilance needs to be taken with the use of heavy metals in hospitals and the environment.


1995 ◽  
Vol 18 (3) ◽  
pp. 191-203 ◽  
Author(s):  
Eva M. Top ◽  
Helene Rore ◽  
Jean-Marc Collard ◽  
Veerle Gellens ◽  
Galina Slobodkina ◽  
...  

2019 ◽  
Vol 8 (7) ◽  
Author(s):  
Olubukola Oluranti Babalola ◽  
Bukola Rhoda Aremu ◽  
Ayansina Segun Ayangbenro

Bacillus cereus NWUAB01 was isolated from a gold-mining site in Vryburg, South Africa, for its multiple heavy metal resistance properties. Here, we report the draft genome sequence of B. cereus NWUAB01 obtained with Illumina sequencing.


Pathogens ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 79 ◽  
Author(s):  
Chumisa C. Dweba ◽  
Oliver T. Zishiri ◽  
Mohamed E. El Zowalaty

Staphylococcus aureus is one of the most important pathogens of humans and animals. Livestock production contributes a significant proportion to the South African Gross Domestic Product. Consequently, the aim of this study was to determine for the first time the prevalence, virulence, antibiotic and heavy metal resistance in livestock-associated S. aureus isolated from South African livestock production systems. Microbial phenotypic methods were used to detect the presence of antibiotic and heavy metal resistance. Furthermore, molecular DNA based methods were used to genetically determine virulence as well as antibiotic and heavy metal resistance determinants. Polymerase chain reaction (PCR) confirmed 217 out of 403 (53.8%) isolates to be S. aureus. Kirby-Bauer disc diffusion method was conducted to evaluate antibiotic resistance and 90.8% of S. aureus isolates were found to be resistant to at least three antibiotics, and therefore, classified as multidrug resistant. Of the antibiotics tested, 98% of the isolates demonstrated resistance towards penicillin G. High resistance was shown against different heavy metals, with 90% (196/217), 88% (192/217), 86% (188/217) and 84% (183/217) of the isolates resistant to 1500 µg/mL concentration of Cadmium (Cd), Zinc (Zn), Lead (Pb) and Copper (Cu) respectively. A total of 10 antimicrobial resistance and virulence genetic determinants were screened for all livestock associated S. aureus isolates. Methicillin-resistant S. aureus (MRSA) isolates were identified, by the presence of mecC, in 27% of the isolates with a significant relationship (p < 0.001)) with the host animal. This is the first report of mecC positive LA-MRSA in South Africa and the African continent. The gene for tetracycline resistance (tetK) was the most frequently detected of the screened genes with an overall prevalence of 35% and the highest prevalence percentage was observed for goats (56.76%) followed by avian species (chicken, duck and wild birds) (42.5%). Virulence-associated genes were observed across all animal host species. The study reports the presence of luks/pv, a gene encoding the PVL toxin previously described to be a marker for community acquired-MRSA, suggesting the crossing of species between human and livestock. The high prevalence of S. aureus from the livestock indicates a major food security and healthcare threat. This threat is further compounded by the virulence of the pathogen, which causes numerous clinical manifestations. The phenomenon of co-selection is observed in this study as isolates exhibited resistance to both antibiotics and heavy metals. Further, all the screened antibiotic and heavy metal resistance genes did not correspond with the phenotypic resistance.


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