Transferable tetracycline resistance in Clostridium perfringens strains of porcine origin

1983 ◽  
Vol 29 (10) ◽  
pp. 1241-1246 ◽  
Author(s):  
Julian I. Rood

These studies represent the first systematic survey of the incidence of conjugative antibiotic resistance in Clostridium perfringens. Ninety-two antibiotic-resistant porcine strains were examined to see if they could donate their antibiotic-resistance determinants to sensitive recipient strains. Fifteen of the 89 tetracycline-resistant strains transferred their tetracycline resistance in mixed-plate mating experiments but no transfer of macrolide–lincosamide resistance was detected. The efficiencies of transfer of tetracycline resistance varied from 1.3 × 10−3 to 1.9 × 10−6 transconjugants per donor cell. Significantly higher transfer efficiencies were observed when both the donor and recipient strains were derivatives of strain CW 362. These values ranged from 3.7 × 10−1 to 4.6 × 10−2 transconjugants per donor cell. This high frequency transfer system should prove invaluable for further genetic studies on this microorganism.


1968 ◽  
Vol 66 (3) ◽  
pp. 471-477 ◽  
Author(s):  
Joan R. Davies ◽  
W. N. Farrant ◽  
A. J. H. Tomlinson

SummaryThe incidence of antibiotic resistant strains of Sh. sonnei isolated in the London area is described. Strains were tested for their ability to transfer resistance to Most strains were resistant to sulphonamide and this resistance was transferable.An increasing proportion of strains was resistant to 800 µg./ml. of streptomycin, but transferable streptomycin resistance was less common and often associated with tetracycline resistance.The proportion of strains resistant to tetracycline fluctuated but this resistance was always transferred.Ampicillin resistance was common; only those strains resistant to 500µg./ml. transferred this resistance.Resistance to other antibiotics was very rare.



Author(s):  
NА Gordinskaya ◽  
EV Boriskina ◽  
DV Kryazhev

Introduction: A large number of infectious processes are associated with opportunistic microorganisms. The phenotype of antibiotic resistance of such pathogens is multidrug-resistant strains with the presence of various β-lactamases. Our objective was to determine the phenotypic and genotypic features of antibiotic resistance of staphylococci, enterobacteria, and non-fermenting Gram-negative bacteria – the cause of infectious diseases in patients of various health facilities of Nizhny Novgorod. Material and methods: Using classical microbiological methods and molecular genetic studies, we analyzed 486 strains of microorganisms isolated from the upper respiratory tract, intestines, urine, and wound discharge of patients in 2019–2020. In all isolates, the phenotype of antibiotic resistance was determined by the disco-diffusion method (Bioanalyse, Turkey) and using the Multiscan FC spectrophotometer (ThermoScientific, Finland) with Microlatest tablets (PLIVA-Lachema, Czech Republic), along with molecular features of resistance mechanisms by PCR on the CFX96 device (BioRad, USA) using AmpliSens kits (Russia). Results and discussion: The results showed that the most prevalent causative agents of infectious diseases (40.7 %) were Gram-negative bacteria, of which Enterobacteriaceae and non-fermenting bacteria accounted for 27.1 % and 13.6 % of cases, respectively. Staphylococci were isolated in 37.6 % of patients: S. aureus and coagulase-negative staphylococci induced 13.4 % and 24.2 % of cases, respectively. The analysis of antibiotic resistance of the isolates showed a high level of antimicrobial resistance in all hospitals, regardless of the isolation locus. The phenotype of methicillin-resistant strains was found in 26.3 % and 37.9 % of S. aureus and coagulase-negative staphylococci, respectively; the mecA gene was found in 89.0 % of methicillin-resistant staphylococci. The highest number of antibiotic-resistant strains among Gram-negative microorganisms was observed in K. pneumoniae, A. baumannii, and P. aeruginosa. We established that 61.7 % of K. pneumoniae, 75.1 % of A. baumannii, and 58.2 % of P. aeruginosa were resistant to carbapenems. The results of molecular genetic studies confirmed the presence of serine carbapenemases KPC and OXA groups in all multidrug-resistant K. pneumoniae and A. baumannii; genes of the metallo-β-lactamase of VIM group were found in 40.9 % strains of P. aeruginosa. The production of numerous β-lactamases and the presence of determinants of antibiotic resistance in the genome determine the virulent properties of opportunistic microorganisms. Conclusion: The antibiotic resistance of opportunistic microorganisms is the cause of developing a chronic infectious process. Today, a wide spread of antibiotic-resistant infectious agents is a serious public health problem, which determines the need for constant microbiological monitoring and studies of molecular mechanisms of resistance to identify the most potent antibiotics and to determine the ways of eradication of multidrug-resistant strains.



Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 885
Author(s):  
Gustavo Di Lallo ◽  
Marco Maria D’Andrea ◽  
Samanta Sennati ◽  
Maria Cristina Thaller ◽  
Luciana Migliore ◽  
...  

The improper use of antibiotics by humans may promote the dissemination of resistance in wildlife. The persistence and spread of acquired antibiotic resistance and human-associated bacteria in the environment, while representing a threat to wildlife, can also be exploited as a tool to monitor the extent of human impact, particularly on endangered animal species. Hence, we investigated both the associated enterobacterial species and the presence of acquired resistance traits in the cloacal microbiota of the critically endangered lesser Antillean iguana (Iguana delicatissima), by comparing two separate populations living in similar climatic conditions but exposed to different anthropic pressures. A combination of techniques, including direct plating, DNA sequencing and antimicrobial susceptibility testing allowed us to characterize the dominant enterobacterial populations, the antibiotic resistant strains and their profiles. A higher frequency of Escherichia coli was found in the samples from the more anthropized site, where multi-drug resistant strains were also isolated. These results confirm how human-associated bacteria as well as their antibiotic-resistance determinants may be transferred to wildlife, which, in turn, may act as a reservoir of antibiotic resistance.



2014 ◽  
Vol 16 (3) ◽  
pp. 455-462 ◽  

<div> <p>Solar simulated heterogeneous photocatalysis (SSHP) with suspended TiO<sub>2</sub> was investigated in the inactivation of tetracycline resistant/sensitive <em>Enterococcus</em> (TRE/TSE) strains in the effluent of an urban wastewater treatment plant (UWTP). The effect of solar simulated disinfection (SSD) on the inactivation of the same <em>Enterococcus</em> strains was investigated as control. SSHP process (0.05 g l<sup>-1</sup> of TiO<sub>2</sub>) was found to be effective in the inactivation of both <em>Enterococcus</em> strains with total inactivation (~7 log unit) observed after 60 min of irradiation. On the contrary, SSD process did not show any significant inactivation after 90 min of irradiation. The effect of both processes on the antibiotic resistance phenotypes of the surviving enterococci was also evaluated. TRE cells surviving the SSHP treatment showed that disinfection process did not affect the antibiotic resistance pattern after 45 min irradiation. The same was observed for the TSE strain. Accordingly, antibiotic resistance can spread into the receiving water body when antibiotic resistant strains survive to disinfection process.</p> </div> <p>&nbsp;</p>



2018 ◽  
pp. 128-131 ◽  
Author(s):  
N. G. Kolosova ◽  
A. B. Kolosova

Despite the fact that acute respiratory infections have viral etiology, the frequency of antibiotic prescriptions accounts for more than 70% in outpatient practice. However, the preventive administration of systemic antibiotics does not reduce the duration of the disease and the incidence of bacterial complications. In addition, the irrational use of antibiotic therapy can lead to the development of antibiotic resistance of infectious disease pathogens. The global problem of antibiotic resistance is seen as a serious threat to public health, and therefore the systemic antibiotic restriction policy is crucial, which helps to reduce the formation of antibiotic-resistant strains of infectious agents. The possibility of using local antibacterial drugs enables optimization of antibiotic therapy and reduces the risk of the development of antibiotic resistance. The article discusses the issues of use of thiamphenicol glycinate acetylcysteinate in various diseases in children.



2007 ◽  
Vol 74 (3) ◽  
pp. 262-268 ◽  
Author(s):  
Ana Belén Flórez ◽  
Morten Danielsen ◽  
Jenni Korhonen ◽  
Joanna Zycka ◽  
Atte von Wright ◽  
...  

In order to establish cut-off values forLactococcus lactisto six antibiotics to distinguish susceptible and intrinsically resistant strains from those having acquired resistances, the minimum inhibitory concentration (MIC) of tetracycline, erythromycin, clindamycin, streptomycin, chloramphenicol and vancomycin was determined in 93 differentLc. lactisstrains using the Etest. These bacterial strains were originally isolated from dairy and animal sources in widely separated geographical locations. Cut-offs were defined on the basis of the distribution of the MICs frequency of the studied antibiotics, which in the absence of acquired determinants should approach to a normal statistical distribution. In general, the new cut-off values proposed in this study are higher than previously defined (European Commission, 2005. The EFSA Journal 223, 1–12). Based on these new values, all the strains tested were susceptible to erythromycin, chloramphenicol and vancomycin, and 79 susceptible to all six antibiotics. However, 11 strains (around 12%) were considered resistant to tetracycline (six of which had been identified after screening of a large collection of lactococci strains for tetracycline resistance) and five (5·4%) resistant to streptomycin. Of these, two fish isolates proved to be resistance to both tetracycline and streptomycin. From the tetracycline resistant strains,tet(M) and mosaictet(L/S) genes were amplified by PCR, demonstrating they harboured acquired antibiotic resistance determinants.



2019 ◽  
Vol 20 (6) ◽  
pp. 1255 ◽  
Author(s):  
Ana Monserrat-Martinez ◽  
Yann Gambin ◽  
Emma Sierecki

Since their discovery in the early 20th century, antibiotics have been used as the primary weapon against bacterial infections. Due to their prophylactic effect, they are also used as part of the cocktail of drugs given to treat complex diseases such as cancer or during surgery, in order to prevent infection. This has resulted in a decrease of mortality from infectious diseases and an increase in life expectancy in the last 100 years. However, as a consequence of administering antibiotics broadly to the population and sometimes misusing them, antibiotic-resistant bacteria have appeared. The emergence of resistant strains is a global health threat to humanity. Highly-resistant bacteria like Staphylococcus aureus (methicillin-resistant) or Enterococcus faecium (vancomycin-resistant) have led to complications in intensive care units, increasing medical costs and putting patient lives at risk. The appearance of these resistant strains together with the difficulty in finding new antimicrobials has alarmed the scientific community. Most of the strategies currently employed to develop new antibiotics point towards novel approaches for drug design based on prodrugs or rational design of new molecules. However, targeting crucial bacterial processes by these means will keep creating evolutionary pressure towards drug resistance. In this review, we discuss antibiotic resistance and new options for antibiotic discovery, focusing in particular on new alternatives aiming to disarm the bacteria or empower the host to avoid disease onset.



mBio ◽  
2011 ◽  
Vol 2 (5) ◽  
Author(s):  
Trudi L. Bannam ◽  
Xu-Xia Yan ◽  
Paul F. Harrison ◽  
Torsten Seemann ◽  
Anthony L. Keyburn ◽  
...  

ABSTRACTThe pathogenesis of avian necrotic enteritis involves NetB, a pore-forming toxin produced by virulent avian isolates ofClostridium perfringenstype A. To determine the location and mobility of thenetBstructural gene, we examined a derivative of the tetracycline-resistant necrotic enteritis strain EHE-NE18, in whichnetBwas insertionally inactivated by the chloramphenicol and thiamphenicol resistance genecatP. Both tetracycline and thiamphenicol resistance could be transferred either together or separately to a recipient strain in plate matings. The separate transconjugants could act as donors in subsequent matings, which demonstrated that the tetracycline resistance determinant and thenetBgene were present on different conjugative elements. Large plasmids were isolated from the transconjugants and analyzed by high-throughput sequencing. Analysis of the resultant data indicated that there were actually three large conjugative plasmids present in the original strain, each with its own toxin or antibiotic resistance locus. Each plasmid contained a highly conserved 40-kb region that included plasmid replication and transfer regions that were closely related to the 47-kb conjugative tetracycline resistance plasmid pCW3 fromC. perfringens. The plasmids were as follows: (i) a conjugative 49-kb tetracycline resistance plasmid that was very similar to pCW3, (ii) a conjugative 82-kb plasmid that contained thenetBgene and other potential virulence genes, and (iii) a 70-kb plasmid that carried thecpb2gene, which encodes a different pore-forming toxin, beta2 toxin.IMPORTANCEThe anaerobic bacteriumClostridium perfringenscan cause an avian gastrointestinal disease known as necrotic enteritis. Disease pathogenesis is not well understood, although the plasmid-encoded pore-forming toxin NetB, is an important virulence factor. In this work, we have shown that the plasmid that carries thenetBgene is conjugative and has a 40-kb region that is very similar to replication and transfer regions found within each of the sequenced conjugative plasmids fromC. perfringens. We also showed that this strain contained two additional large plasmids that were also conjugative and carried a similar 40-kb region. One of these plasmids encoded beta2 toxin, and the other encoded tetracycline resistance. To our knowledge, this is the first report of a bacterial strain that carries three closely related but different independently conjugative plasmids. These results have significant implications for our understanding of the transmission of virulence and antibiotic resistance genes in pathogenic bacteria.



2018 ◽  
Vol 84 (19) ◽  
Author(s):  
Mengfei Peng ◽  
Serajus Salaheen ◽  
Robert L. Buchanan ◽  
Debabrata Biswas

ABSTRACT Microbial horizontal gene transfer is a continuous process that shapes bacterial genomic adaptation to the environment and the composition of concurrent microbial ecology. This includes the potential impact of synthetic antibiotic utilization in farm animal production on overall antibiotic resistance issues; however, the mechanisms behind the evolution of microbial communities are not fully understood. We explored potential mechanisms by experimentally examining the relatedness of phylogenetic inference between multidrug-resistant Salmonella enterica serovar Typhimurium isolates and pathogenic Salmonella Typhimurium strains based on genome-wide single-nucleotide polymorphism (SNP) comparisons. Antibiotic-resistant S. Typhimurium isolates in a simulated farm environment barely lost their resistance, whereas sensitive S. Typhimurium isolates in soils gradually acquired higher tetracycline resistance under antibiotic pressure and manipulated differential expression of antibiotic-resistant genes. The expeditious development of antibiotic resistance and the ensuing genetic alterations in antimicrobial resistance genes in S. Typhimurium warrant effective actions to control the dissemination of Salmonella antibiotic resistance. IMPORTANCE Antibiotic resistance is attributed to the misuse or overuse of antibiotics in agriculture, and antibiotic resistance genes can also be transferred to bacteria under environmental stress. In this study, we report a unidirectional alteration in antibiotic resistance from susceptibility to increased resistance. Highly sensitive Salmonella enterica serovar Typhimurium isolates from organic farm systems quickly acquired tetracycline resistance under antibiotic pressure in simulated farm soil environments within 2 weeks, with expression of antibiotic resistance-related genes that was significantly upregulated. Conversely, originally resistant S. Typhimurium isolates from conventional farm systems lost little of their resistance when transferred to environments without antibiotic pressure. Additionally, multidrug-resistant S. Typhimurium isolates genetically shared relevancy with pathogenic S. Typhimurium isolates, whereas susceptible isolates clustered with nonpathogenic strains. These results provide detailed discussion and explanation about the genetic alterations and simultaneous acquisition of antibiotic resistance in S. Typhimurium in agricultural environments.



Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 162 ◽  
Author(s):  
Monica Francesca Blasi ◽  
Luciana Migliore ◽  
Daniela Mattei ◽  
Alice Rotini ◽  
Maria Cristina Thaller ◽  
...  

Sea turtles have been proposed as health indicators of marine habitats and carriers of antibiotic-resistant bacterial strains, for their longevity and migratory lifestyle. Up to now, a few studies evaluated the antibacterial resistant flora of Mediterranean loggerhead sea turtles (Caretta caretta) and most of them were carried out on stranded or recovered animals. In this study, the isolation and the antibiotic resistance profile of 90 Gram negative bacteria from cloacal swabs of 33 Mediterranean wild captured loggerhead sea turtles are described. Among sea turtles found in their foraging sites, 23 were in good health and 10 needed recovery for different health problems (hereafter named weak). Isolated cloacal bacteria belonged mainly to Enterobacteriaceae (59%), Shewanellaceae (31%) and Vibrionaceae families (5%). Although slight differences in the bacterial composition, healthy and weak sea turtles shared antibiotic-resistant strains. In total, 74 strains were endowed with one or multi resistance (up to five different drugs) phenotypes, mainly towards ampicillin (~70%) or sulfamethoxazole/trimethoprim (more than 30%). Hence, our results confirmed the presence of antibiotic-resistant strains also in healthy marine animals and the role of the loggerhead sea turtles in spreading antibiotic-resistant bacteria.



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