multidrug-resistant bacteria

{{Short description|Bacteria resistant to three or more classes of antimicrobial drugs}}

Multidrug-resistant (MDR) bacteria are bacteria that are resistant to three or more classes of antimicrobial drugs.{{Cite journal|last1=Magiorakos|first1=A.-P.|last2=Srinivasan|first2=A.|last3=Carey|first3=R.B.|last4=Carmeli|first4=Y.|last5=Falagas|first5=M.E.|last6=Giske|first6=C.G.|last7=Harbarth|first7=S.|last8=Hindler|first8=J.F.|last9=Kahlmeter|first9=G.|last10=Olsson-Liljequist|first10=B.|last11=Paterson|first11=D.L.|date=March 2012|title=Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance|journal=Clinical Microbiology and Infection|language=en|volume=18|issue=3|pages=268–281|doi=10.1111/j.1469-0691.2011.03570.x|pmid=21793988|doi-access=free}} MDR bacteria have seen an increase in prevalence in recent years{{Clarify|reason=Hard to tell what recent means in the context of when the last edit was made|date=April 2023}}{{Cite journal|last1=Bae|first1=Songmee|last2=Lee|first2=Jaehoon|last3=Lee|first3=Jaehwa|last4=Kim|first4=Eunah|last5=Lee|first5=Sunhwa|last6=Yu|first6=Jaeyon|last7=Kang|first7=Yeonho|date=January 2010|title=Antimicrobial Resistance in Haemophilus influenzae Respiratory Tract Isolates in Korea: Results of a Nationwide Acute Respiratory Infections Surveillance|url= |journal=Antimicrobial Agents and Chemotherapy|language=en|volume=54|issue=1|pages=65–71|doi=10.1128/AAC.00966-09|issn=0066-4804|pmc=2798543|pmid=19884366}} and pose serious risks to public health. MDR bacteria can be broken into 3 main categories: Gram-positive, Gram-negative, and other (acid-stain). These bacteria employ various adaptations to avoid or mitigate the damage done by antimicrobials. With increased access to modern medicine there has been a sharp increase in the amount of antibiotics consumed.{{Cite news|last=Sample|first=Ian|date=2018-03-26|title=Calls to rein in antibiotic use after study shows 65% increase worldwide|language=en-GB|work=The Guardian|url=https://www.theguardian.com/science/2018/mar/26/calls-to-rein-in-antibiotic-use-after-study-shows-65-increase-worldwide|access-date=2020-11-09|issn=0261-3077}} Given the abundant use of antibiotics there has been a considerable increase in the evolution of antimicrobial resistance factors, now outpacing the development of new antibiotics.{{Cite journal|last=Ventola|first=C. Lee|date=April 2015|title=The antibiotic resistance crisis: part 1: causes and threats|journal=P & T: A Peer-Reviewed Journal for Formulary Management|volume=40|issue=4|pages=277–283|issn=1052-1372|pmc=4378521|pmid=25859123}}

Examples identified as serious threats to public health

Examples of MDR bacteria identified as serious threats to public health include:{{Cite web|last=CDC|date=2020-10-28|title=Antibiotic-resistant Germs: New Threats|url=https://www.cdc.gov/drugresistance/biggest-threats.html|access-date=2020-11-09|website=Centers for Disease Control and Prevention|language=en-us}}

;Gram-positive MDR bacteria

;Gram-negative MDR bacteria

;Other MDR bacteria

Mycobacterium tuberculosis

Microbial adaptations

MDR bacteria employ a plurality of adaptations to overcome the environmental insults caused by antibiotics. Bacteria are capable of sharing these resistance factors in a process called horizontal gene transfer where resistant bacteria share genetic information that encodes resistance to the naive population.{{Cite journal |last1=Arnold |first1=Brian J. |last2=Huang |first2=I-Ting |last3=Hanage |first3=William P. |date=April 2022 |title=Horizontal gene transfer and adaptive evolution in bacteria |url=https://www.nature.com/articles/s41579-021-00650-4 |journal=Nature Reviews Microbiology |language=en |volume=20 |issue=4 |pages=206–218 |doi=10.1038/s41579-021-00650-4 |pmid=34773098 |s2cid=244076968 |issn=1740-1526|url-access=subscription }}

Antibiotic inactivation: bacteria create proteins that can prevent damage caused by antibiotics, they can do this in two ways. First, inactivating or modifying the antibiotic so that it can no longer interact with its target. Second, degrading the antibiotic directly.{{Cite journal|last1=Munita|first1=Jose M.|last2=Arias|first2=Cesar A.|date=April 2016|title=Mechanisms of Antibiotic Resistance|journal=Microbiology Spectrum|volume=4|issue=2|doi=10.1128/microbiolspec.VMBF-0016-2015|issn=2165-0497|pmc=4888801|pmid=27227291}}
Multidrug efflux pumps: The use of transporter proteins to expel the antibiotic.{{Cite journal|last1=Du|first1=Dijun|last2=Wang-Kan|first2=Xuan|last3=Neuberger|first3=Arthur|last4=van Veen|first4=Hendrik W.|last5=Pos|first5=Klaas M.|last6=Piddock|first6=Laura J. V.|last7=Luisi|first7=Ben F.|date=September 2018|title=Multidrug efflux pumps: structure, function and regulation|url=https://www.nature.com/articles/s41579-018-0048-6|journal=Nature Reviews Microbiology|language=en|volume=16|issue=9|pages=523–539|doi=10.1038/s41579-018-0048-6|pmid=30002505|s2cid=49666287|issn=1740-1534|url-access=subscription}}
Modification of target sites: mutating or modifying elements of the bacteria structure to prevent interaction with the antibiotic.
Structural modifications: mutating or modifying global elements of cell to adapt to Antibiotic (Such as increased acid tolerance to an acidic antimicrobial)

Alternative antimicrobial methods

= Phage therapy =

Bacteriophage therapy, commonly known as 'phage therapy,' uses bacteria-specific viruses to kill antibiotic resistant bacteria. Phage therapy offers considerably higher specificity as the phage can be engineered to only infect a certain bacteria species.{{Cite journal|last1=Lin|first1=Derek M|last2=Koskella|first2=Britt|last3=Lin|first3=Henry C|date=2017|title=Phage therapy: An alternative to antibiotics in the age of multi-drug resistance|journal=World Journal of Gastrointestinal Pharmacology and Therapeutics|language=en|volume=8|issue=3|pages=162–173|doi=10.4292/wjgpt.v8.i3.162|issn=2150-5349|pmc=5547374|pmid=28828194 |doi-access=free }} Phage therapy also allows for the possibility of biofilm penetration in cases where antibiotics are ineffective due to the increased resistance of biofilm-forming pathogens. One major drawback to phage therapy is the evolution of phage-resistant microbes which was seen in a majority of phage therapy experiments aimed to treat sepsis and intestinal infection.{{Cite journal|last=Oechslin|first=Frank|date=2018-06-30|title=Resistance Development to Bacteriophages Occurring during Bacteriophage Therapy|journal=Viruses|language=en|volume=10|issue=7|pages=351|doi=10.3390/v10070351|issn=1999-4915|pmc=6070868|pmid=29966329|doi-access=free}} Recent studies suggest that development of phage resistance comes as a trade-off for antibiotic resistance and can be used to create antibiotic-sensitive populations.{{Cite journal|last1=Chan|first1=Benjamin K.|last2=Sistrom|first2=Mark|last3=Wertz|first3=John E.|last4=Kortright|first4=Kaitlyn E.|last5=Narayan|first5=Deepak|last6=Turner|first6=Paul E.|date=July 2016|title=Phage selection restores antibiotic sensitivity in MDR Pseudomonas aeruginosa|url= |journal=Scientific Reports|language=en|volume=6|issue=1|pages=26717|doi=10.1038/srep26717|issn=2045-2322|pmc=4880932|pmid=27225966|bibcode=2016NatSR...626717C}}

References

Category:Microbiology

Category:Public health

Category:Symbiosis

Category:Antibiotics

Category:Antibiotic-resistant bacteria