Antibiotic Resistance, the Horrendous Consequences of Bacterial Sex

2021 ◽  
pp. 111-116
Author(s):  
Thomas E. Schindler
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Bacterial Strains ◽  
Antibiotic Resistant ◽  
Methicillin Resistant ◽  
Postwar Japan ◽  
Resistant Genes ◽  
Rapid Emergence ◽  
Multiple Antibiotics

This chapter reviews how bacterial sex explains the rapid emergence of superbugs that are resistant to multiple antibiotics, the so-called MDR pathogens. Millions of years before humans evolved, bacteria invented antibiotics and the defensive molecules that make some bacteria resistant to an antibiotic. Therefore, antibiotic resistant genes pre-exist in many bacterial strains, literally lying in wait to emerge in superbugs. In postwar Japan, bacteriologists discovered the first MDR pathogens during dysentery outbreaks. Researchers demonstrated that the genes for resistance to several antibiotics were transferred by bacterial sex—from normal flora to the dysentery pathogens—all together and “at one stroke.” Methicillin was intentionally designed to treat penicillin-resistant infections. Only three years after its introduction of, hospitals began to find methicillin-resistant Staphylococcus aureus (MRSA). Gerard Wright coined the term resistome to signify “the global collection of resistance genes that have been readily available to pathogens for millennia.”

scholarly journals Role of biofilm-specific antibiotic resistance genes PA0756-0757, PA5033 and PA2070 in Pseudomonas aeruginosa

2018 ◽  
Author(s):  
Prasanth Manohar ◽  
Thamaraiselvan Shanthini ◽  
Reethu Ann Philip ◽  
Subramani Ramkumar ◽  
Manali Kale ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Biofilm Formation ◽  
Tamil Nadu ◽  
Antibiotic Resistance Genes ◽  
Clinical Samples ◽  
Cross Sectional ◽  
Antibiotic Resistant ◽  
Resistant Genes

AbstractTo evaluate the presence of biofilm-specific antibiotic-resistant genes, PA0756-0757, PA5033 and PA2070 in Pseudomonas aeruginosa isolated from clinical samples in Tamil Nadu. For this cross-sectional study, 24 clinical isolates (included pus, urine, wound, and blood) were collected from two diagnostic centers in Chennai from May 2015 to February 2016. Biofilm formation was assessed using microtiter dish biofilm formation assay and minimal inhibitory concentration (MIC) and minimal bactericidal concentrations (MBC) were determined for planktonic and biofilm cells (MBC assay). Further, PCR amplification of biofilm-specific antibiotic resistance genes PA0756-0757, PA5033 and PA2070 were performed. Biofilm formation was found to be moderate/strong in 16 strains. MBC for planktonic cells showed that 4, 7, 10 and 14 strains were susceptible to gentamicin, ciprofloxacin, meropenem and colistin respectively. In MBC assay for biofilm cells (MBC-B), all the 16 biofilm producing strains were resistant to ciprofloxacin and gentamicin whereas nine and four were resistant to meropenem, and colistin respectively. The biofilm-specific antibiotic-resistant genes PA0756-0757 was found in 10 strains, 6 strains with PA5033 and 9 strains with PA2070 that were found to be resistant phenotypically. This study highlighted the importance of biofilm-specific antibiotic resistance genes PA0756-0757, PA5033, and PA2070 in biofilm-forming P. aeruginosa.

scholarly journals Structural analysis of avibactam-mediated activation of the bla and mec divergons in methicillin-resistant Staphylococcus aureus

2020 ◽  
Vol 295 (32) ◽  
pp. 10870-10884 ◽  
Author(s):  
J. Andrew N. Alexander ◽  
Mariia Radaeva ◽  
Dustin T. King ◽  
Henry F. Chambers ◽  
Artem Cherkasov ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Physiological Role ◽  
Antibiotic Resistance Genes ◽  
Binding Pocket ◽  
Methicillin Resistant ◽  
Mortality And Morbidity ◽  
Expression Of Genes ◽  
Genes Encoding

Methicillin-resistant Staphylococcus aureus (MRSA) infections cause significant mortality and morbidity globally. MRSA resistance to β-lactam antibiotics is mediated by two divergons that control levels of a β-lactamase, PC1, and a penicillin-binding protein poorly acylated by β-lactam antibiotics, PBP2a. Expression of genes encoding these proteins is controlled by two integral membrane proteins, BlaR1 and MecR1, which both have an extracellular β-lactam–binding sensor domain. Here, we solved the X-ray crystallographic structures of the BlaR1 and MecR1 sensor domains in complex with avibactam, a diazabicyclooctane β-lactamase inhibitor at 1.6–2.0 Å resolution. Additionally, we show that S. aureus SF8300, a clinically relevant strain from the USA300 clone of MRSA, responds to avibactam by up-regulating the expression of the blaZ and pbp2a antibiotic-resistance genes, encoding PC1 and PBP2a, respectively. The BlaR1–avibactam structure of the carbamoyl-enzyme intermediate revealed that avibactam is bound to the active-site serine in two orientations ∼180° to each other. Although a physiological role of the observed alternative pose remains to be validated, our structural results hint at the presence of a secondary sulfate-binding pocket that could be exploited in the design of future inhibitors of BlaR1/MecR1 sensor domains or the structurally similar class D β-lactamases. The MecR1–avibactam structure adopted a singular avibactam orientation similar to one of the two states observed in the BlaR1–avibactam structure. Given avibactam up-regulates expression of blaZ and pbp2a antibiotic resistance genes, we suggest further consideration and research is needed to explore what effects administering β-lactam–avibactam combinations have on treating MRSA infections.

scholarly journals Profile of antibiotic-resistant and presence of methicillin-resistant Staphylococcus aureus from nasal swab of dogs from several animal clinics in Surabaya, Indonesia

2020 ◽  
Vol 6 (1) ◽  
pp. 90-94
Author(s):  
Vega Decline ◽  
Mustofa Helmi Effendi ◽  
Reina Puspita Rahmaniar ◽  
Sheila Marty Yanestria ◽  
Nenny Harijani
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Nasal Swab ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antibiotic Sensitivity ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Antibiotic Resistant ◽  
Methicillin Resistant ◽  
Oxacillin Resistance

Aim: The research was to investigate the antibiotic resistance profile and to screen for methicillin-resistant Staphylococcus aureus (MRSA) from nasal mucosa swab of dogs. Materials and Methods: The samples were collected from three pet clinics, three K9 units, one veterinary teaching hospital, and one kennel in Surabaya. Of the 50 total samples, 24 confirmed S. aureus strains, which were used for antibiotic sensitivity tests using a disk diffusion method and screening of MRSA used oxacillin resistance screening for base (ORSAB). Results: This study showed that there were differences in antibiotic resistance patterns among different locations. Fourteen isolates were screened for MRSA by culture on ORSAB. Conclusion: MRSA carriage was found on nasal swab of dogs, and dogs can act as reservoir of MRSA for spreading to human health. Keywords: antibiotic-resistant, dogs, methicillin-resistant Staphylococcus aureus, Staphylococcus aureus.

scholarly journals Prevalence and Expression of Genes of Type II Antitoxin Toxin Systems in Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

2021 ◽  
pp. 96-105
Author(s):  
M. Rahimkhani ◽  
A. Mordadi ◽  
P. Karami ◽  
O. Zarei
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Growth Stage ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antimicrobial Effect ◽  
Type Ii ◽  
Bacterial Strains ◽  
Methicillin Resistant ◽  
Toxin Genes ◽  
Logarithmic Growth

Objectives: Antibiotic resistance of bacteria has been increasing in recent years and reports indicate that some bacterial strains are even resistant to the last treatment line. The survey of MazEF antitoxin-toxin genes in 84 strain of MRSA and and the antimicrobial effect of supernatants on the logarithmic growth stage of the bacteria. Methods: In this study, 84 strains of MRSA were collected. The patients included 48 males and 36 females with a mean age of 39 years.  The primers for Staphylococcus aureus type II antitoxin genes were designed. In the first step, using the mecA primer and PCR, the strains were genetically examined to confirm methicillin-resistant Staphylococcus aureus. In the next step, the frequency of MazEF antitoxin-toxin genes was examined. Results: All strains of methicillin-resistant Staphylococcus aureus had the F maz gene except one. The highest antibiotic resistance was related to the strains isolated from the wound and the lowest resistance was related to the strains isolated from the urine. the effect of the supernatant obtained in the death phase of Staphylococcus aureus was assessed and the antimicrobial effect of these supernatants on the logarithmic growth stage of the bacteria was measured. Conclusion: since previous studies showed the antimicrobial effect of this supernatant on many other bacteria, a type II system was suspected that was confirmed by the results.

scholarly journals Seftarolin, Antibiotik Baru dengan Aktivitas Anti-MRSA: Sebuah Kajian Efektivitas, Keamanan, dan Biaya Penggunaan

2020 ◽  
Vol 6 (1) ◽  
pp. 160-180
Author(s):  
Steven Victoria Halim ◽  
Eko Setiawan
Keyword(s):  
Staphylococcus Aureus ◽  
Medical Practice ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Efficacy And Safety ◽  
Medical Field ◽  
Antibiotic Resistant ◽  
Methicillin Resistant ◽  
New Antibiotics ◽  
Multiple Antibiotics

A growing problem in the medical field is the development of antibiotic resistant pathogens. One reason this development is so important is that in recent years there is a shortage of new antibiotics in development to combat resistant pathogens. It worths to mention that while 19 new antibiotics were released in the period 1980 to 1984, this had dropped to just three in the period 2005 to 2009. Ironically, the shortage of new antibiotics occur in the era where growing number of pathogens develop resistance to multiple antibiotics that previously effectively used to treat the infections. As a consequent, it is essential that the efficacy of last resort antibiotics, including the new antibiotics, be maintained as long as possible. Ceftaroline is a new antibiotic in Indonesia market which has methicillin-resistant Staphylococcus aureus activity and it belongs to the cephalosporins. Further understanding related to basic profile of ceftaroline, efficacy and safety, cost, and place in therapy is needed to optimize the responsible used of ceftaroline in daily medical practice

scholarly journals Deciphering pathogenicity and antibiotic resistance islands in methicillin-resistant Staphylococcus aureus genomes

Open Biology ◽  
2017 ◽  
Vol 7 (12) ◽  
pp. 170094 ◽  
Author(s):  
Mehul Jani ◽  
Soham Sengupta ◽  
Kelsey Hu ◽  
Rajeev K. Azad
Keyword(s):  
Staphylococcus Aureus ◽  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Genomic Islands ◽  
Hospital Environment ◽  
Gene Clustering ◽  
Methicillin Resistant ◽  
Modern Hospital

Staphylococcus aureus is a versatile pathogen that is capable of causing infections in both humans and animals. It can cause furuncles, septicaemia, pneumonia and endocarditis. Adaptation of S. aureus to the modern hospital environment has been facilitated, in part, by the horizontal acquisition of drug resistance genes, such as mecA gene that imparts resistance to methicillin. Horizontal acquisitions of islands of genes harbouring virulence and antibiotic resistance genes have made S. aureus resistant to commonly used antibiotics. To decipher genomic islands (GIs) in 22 hospital- and 9 community-associated methicillin-resistant S. aureus strains and classify a subset of GIs carrying virulence and resistance genes as pathogenicity and resistance islands respectively, we applied a host of methods for localizing genomic islands in prokaryotic genomes. Surprisingly, none of the frequently used GI prediction methods could perform well in delineating the resistance islands in the S. aureus genomes. Rather, a gene clustering procedure exploiting biases in codon usage for identifying horizontally transferred genes outperformed the current methods for GI detection, in particular in identifying the known islands in S. aureus including the SCC mec island that harbours the mecA resistance gene. The gene clustering approach also identified novel, as yet unreported islands, with many of these found to harbour virulence and/or resistance genes. These as yet unexplored islands may provide valuable information on the evolution of drug resistance in S. aureus .

scholarly journals Ctriporin, a New Anti-Methicillin-Resistant Staphylococcus aureus Peptide from the Venom of the Scorpion Chaerilus tricostatus

2011 ◽  
Vol 55 (11) ◽  
pp. 5220-5229 ◽  
Author(s):  
Zheng Fan ◽  
Luyang Cao ◽  
Yawen He ◽  
Jun Hu ◽  
Zhiyong Di ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Micrococcus Luteus ◽  
Bactericidal Effect ◽  
Skin Infections ◽  
Bacterial Strains ◽  
Topical Antibiotic ◽  
Antibiotic Resistant ◽  
Methicillin Resistant ◽  
Content Type

ABSTRACTAntibiotic-resistant microbes, such as methicillin-resistantStaphylococcus aureus, seriously threaten human health. The outbreak of “superbugs” in recent years emphasizes once again the need for the development of new antimicrobial agents or resources. Antimicrobial peptides have an evident bactericidal effect against multidrug-resistant pathogens. In the present study, a new antimicrobial peptide, ctriporin, was cloned and characterized from the venom of the scorpionChaerilus tricostatus, an animal which has not yet been explored for toxic peptide resources. The MICs of ctriporin againstStaphylococcus aureus,Bacillus thuringiensis,Bacillus subtilis,Micrococcus luteus, andCandida albicansare 5 to 20 μg/ml. Meanwhile, it MIC against clinical antibiotic-resistant bacterial strains is 10 μg/ml. Furthermore, the potential for ctriporin to be used as a topical antibiotic for treating staphylococcal skin infections was investigated. External use of the peptide ctriporin dramatically decreased the bacterial counts and cured skin infections in mice. In addition, ctriporin demonstrates antimicrobial efficacy via the bactericidal mechanism of rapid cell lysis. Together, these results suggest the potential of developing ctriporin as a new topical antibiotic.

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