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1.
AMA J Ethics ; 26(6): E472-478, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38833422

ABSTRACT

Poor-quality antimicrobial medicines continue to proliferate across supply chains, threatening patients' health and safety, especially in low- and middle-income regions. This article discusses consequences and risks of antimicrobial resistance and other ways in which antimicrobial medicines can be of poor quality and recommends regulatory and policy reforms to help maintain supply chain resilience and quality of antimicrobial medicines.


Subject(s)
Anti-Infective Agents , Humans , Anti-Infective Agents/therapeutic use , Global Health , Drug Resistance, Microbial , Health Policy
2.
J Infect Dev Ctries ; 18(4): 550-555, 2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38728649

ABSTRACT

INTRODUCTION: Pakistan has been experiencing an extensively drug-resistant (XDR) outbreak of typhoid for some years. We sought to evaluate how the COVID-19 pandemic impacted typhoid epidemiology in Pakistan, from the beginning of the pandemic in 2020 through the end of 2022, and the reduction of COVID-19 cases. METHODOLOGY: We compared national public COVID-19 data with retrospectively obtained patient data of confirmed S. Typhi isolates between January 2019 and December 2022 from Shaukat Khanum Memorial Cancer Hospital and Research Centre and the hospital's extended network of laboratory collection centers across Pakistan. RESULTS: We observed that during the early onset of the COVID-19 pandemic and COVID-19 peaks, typhoid positivity generally decreased. This suggests that restrictions and non-pharmaceutical interventions that limited social interactions and promoted good sanitation and hygiene practices had a positive secondary effect on typhoid. This led to an overall yearly decrease in typhoid positivity between 2019 to 2021. However, the percentage of S. Typhi cases isolated that were ceftriaxone-resistant continued to increase, suggesting the continued dominance of XDR typhoid in Pakistan. In 2022, with the alleviation of pandemic restrictions, we observed increased typhoid positivity and COVID-19 and typhoid positivity started to follow similar trends. CONCLUSIONS: Given the continued presence of COVID-19 along with XDR typhoid in Pakistan, it will be imperative to use differential testing to ensure that the epidemiology of each reported is accurate, the spread of each it contained, and that antibiotics are not misused. The use of approved vaccinations will lessen the burden of both diseases.


Subject(s)
COVID-19 , Salmonella typhi , Typhoid Fever , Typhoid Fever/epidemiology , Pakistan/epidemiology , Humans , COVID-19/epidemiology , COVID-19/prevention & control , Salmonella typhi/drug effects , Salmonella typhi/isolation & purification , Retrospective Studies , SARS-CoV-2 , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology
3.
AMA J Ethics ; 26(4): E341-347, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38564750

ABSTRACT

Reliable, adequate supply of essential items, including quality-assured medicines, is hard to maintain in refugee camps in low- and middle-income countries. Disruption of medicine supply chains delays treatment for displaced persons and drives procurement of poor-quality products, often from unauthorized or unlicensed sellers. This article explains how current strategies and policies disrupt reliable flow of safe medicines to refugee camps and calls on stakeholders to rigorously map medicine supply chains to refugee camps, which would help identify strategies to improve displaced persons' access to quality-assured medicines.


Subject(s)
Health Services Accessibility , Refugees , Humans
4.
Mol Microbiol ; 121(2): 196-212, 2024 02.
Article in English | MEDLINE | ID: mdl-37918886

ABSTRACT

Infections caused by Acinetobacter baumannii, a Gram-negative opportunistic pathogen, are difficult to eradicate due to the bacterium's propensity to quickly gain antibiotic resistances and form biofilms, a protective bacterial multicellular community. The A. baumannii DNA damage response (DDR) mediates the antibiotic resistance acquisition and regulates RecA in an atypical fashion; both RecALow and RecAHigh cell types are formed in response to DNA damage. The findings of this study demonstrate that the levels of RecA can influence formation and dispersal of biofilms. RecA loss results in surface attachment and prominent biofilms, while elevated RecA leads to diminished attachment and dispersal. These findings suggest that the challenge to treat A. baumannii infections may be explained by the induction of the DDR, common during infection, as well as the delicate balance between maintaining biofilms in low RecA cells and promoting mutagenesis and dispersal in high RecA cells. This study underscores the importance of understanding the fundamental biology of bacteria to develop more effective treatments for infections.


Subject(s)
Acinetobacter baumannii , Acinetobacter baumannii/metabolism , DNA Damage , Biofilms , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/metabolism , Drug Resistance, Multiple, Bacterial
6.
Sci Rep ; 13(1): 7801, 2023 05 13.
Article in English | MEDLINE | ID: mdl-37179426

ABSTRACT

While wastewater is understood to be a critically important reservoir of antimicrobial resistance due to the presence of multiple antibiotic residues from industrial and agricultural runoff, there is little known about the effects of antibiotic interactions in the wastewater on the development of resistance. We worked to fill this gap in quantitative understanding of antibiotic interaction in constant flow environments by experimentally monitoring E. coli populations under subinhibitory concentrations of combinations of antibiotics with synergistic, antagonistic, and additive interactions. We then used these results to expand our previously developed computational model to account for the effects of antibiotic interaction. We found that populations grown under synergistic and antagonistic antibiotic conditions exhibited significant differences from predicted behavior. E. coli populations grown with synergistically interacting antibiotics developed less resistance than predicted, indicating that synergistic antibiotics may have a suppressive effect on resistance development. Furthermore E. coli populations grown with antagonistically interacting antibiotics showed an antibiotic ratio-dependent development of resistance, suggesting that not only antibiotic interaction, but relative concentration is important in predicting resistance development. These results provide critical insight for quantitatively understanding the effects of antibiotic interactions in wastewater and provide a basis for future studies in modelling resistance in these environments.


Subject(s)
Anti-Bacterial Agents , Wastewater , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Escherichia coli , Drug Resistance, Bacterial
7.
Am J Trop Med Hyg ; 108(3): 465-469, 2023 03 01.
Article in English | MEDLINE | ID: mdl-36746662

ABSTRACT

Health care among forcibly displaced persons is frequently driven by siloed approaches. Aspects of the built environment, social factors, and the bidirectional relationship between the changing ecosystem and residents are often ignored in health policy design and implementation. While recognizing factors that create a preference for siloed approaches and appreciating the work of humanitarian agencies, we argue for a new data-driven and holistic approach to understand the health of the forcibly displaced. It should be rooted in the realities of the emergence of new diseases, dynamic demographics, and degrading environments around the displaced communities. Such an approach envisions refugee and internally displaced camps as dynamic, complex ecosystems that alter, and are altered by, spatial and temporal factors. At the root of this approach is the necessity to work across disciplines, to think holistically, to go beyond treating single ailments, and to develop ethical approaches that provide dignity to those who are forcibly displaced.


Subject(s)
Ecosystem , Refugees , Humans
8.
bioRxiv ; 2023 Feb 10.
Article in English | MEDLINE | ID: mdl-36798199

ABSTRACT

While wastewater is understood to be a critically important reservoir of antimicrobial resistance due to the presence of multiple antibiotic residues from industrial and agricultural runoff, there is little known about the effects of antibiotic interactions in the wastewater on the development of resistance. We worked to fill this gap in quantitative understanding of antibiotic interaction in constant flow environments by experimentally monitoring E. coli populations under subinhibitory concentrations of combinations of antibiotics with synergistic, antagonistic, and additive interactions. We then used these results to expand our previously developed computational model to account for the complex effects of antibiotic interaction. We found that while E. coli populations grown in additively interacting antibiotic combinations grew predictably according to the previously developed model, those populations grown under synergistic and antagonistic antibiotic conditions exhibited significant differences from predicted behavior. E. coli populations grown in the condition with synergistically interacting antibiotics developed less resistance than predicted, indicating that synergistic antibiotics may have a suppressive effect on antimicrobial resistance development. Furthermore E. coli populations grown in the condition with antagonistically interacting antibiotics showed an antibiotic ratio-dependent development of resistance, suggesting that not only antibiotic interaction, but relative concentration is important in predicting resistance development. These results provide critical insight for quantitatively understanding the effects of antibiotic interactions in wastewater and provide a basis for future studies in modelling resistance in these environments. Importance: Antimicrobial resistance (AMR) is a growing global threat to public health expected to impact 10 million people by 2050, driving mortality rates globally and with a disproportionate effect on low- and middle-income countries. Communities in proximity to wastewater settings and environmentally contaminated surroundings are at particular risk due to resistance stemming from antibiotic residues from industrial and agricultural runoff. Currently, there is a limited quantitative and mechanistic understanding of the evolution of AMR in response to multiple interacting antibiotic residues in constant flow environments. Using an integrated computational and experimental methods, we find that interactions between antibiotic residues significantly affect the development of resistant bacterial populations.

9.
Am J Trop Med Hyg ; 108(2): 278-284, 2023 02 01.
Article in English | MEDLINE | ID: mdl-36623485

ABSTRACT

Typhoid fever, caused by Salmonella enterica serovar Typhi (S. Typhi), is a life-threatening bacterial infection. Recently, an outbreak of a new sublineage of extensively drug resistant (XDR) S. Typhi emerged in Pakistan in the province of Sindh. This sublineage had both a composite multidrug resistance transposon integrated on the chromosome and an acquired IncY plasmid carrying the extended spectrum beta-lactamase, blaCTX-M-15, which conferred resistance to third-generation cephalosporins. We observed previously that XDR typhoid had spread beyond the originating southern Sindh Province. Thus, we sought to determine the genetic diversity of 58 ceftriaxone-resistant S. Typhi clinical isolates by whole genome sequencing collected across Pakistan from November 2018 to December 2020 to provide insights into the molecular epidemiology of the evolving outbreak. We identify multiple novel genomic integrations of the extended spectrum beta-lactamase gene into the chromosome in S. Typhi, revealing the existence of various XDR typhoid variants circulating in the country. Notably, the integration of the IncY plasmid bearing antibiotic resistance genes may allow for subsequent plasmid acquisition by these variants, potentially leading to further plasmid-borne multidrug resistance. Our results can inform containment initiatives, help track associated outcomes and international spread, and help determine how widespread the risk is.


Subject(s)
Typhoid Fever , Humans , Typhoid Fever/drug therapy , Typhoid Fever/epidemiology , Typhoid Fever/microbiology , Pakistan/epidemiology , Salmonella typhi/genetics , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , beta-Lactamases/genetics
10.
Ther Innov Regul Sci ; 57(1): 121-131, 2023 01.
Article in English | MEDLINE | ID: mdl-36006562

ABSTRACT

BACKGROUND: Ensuring good quality of antibiotics is essential for desired health outcomes. Risk assessment of products for quality issues arising along the manufacturing and supply chain can thus have an important role in surveillance and management of interventions designed to reduce the burden of substandard antibiotics. Demonstrated and validated risk assessments are currently limited. OBJECTIVES: The objective of this study was to investigate whether a comparative risk assessment framework, which adapts the WHO criteria for estimating risks for quality issues posed by individual medicines, is applicable and can identify antibiotics with a higher relative risk of substandard prevalence. METHODS: For a proof-of-concept study, a set of antibiotics from the WHO essential medicines list was selected. Quantitative and qualitative data were extracted for each risk assessment criteria pertaining to severity and probability. A final risk matrix was then compared to field data for validation. RESULTS: Antibiotic products were classified by relative risk. Of all the antibiotic products assessed (n = 28), 32% were categorized as highest risk, 46% as high risk, 18% as medium risk, and 4% as lowest risk. The comparison of the risk scores and incidence of quality failure from the USP Medicines Quality Database showed significant correlation. CONCLUSION: The framework and extracted data sets appear applicable to determine relative risk for substandard antibiotics. Results of the risk matrix may be valuable for guiding pharmacovigilance, surveillance strategies, standardizing risk-based approaches, and mitigation efforts. Refinement with increased data availability may improve results.


Subject(s)
Anti-Bacterial Agents , Counterfeit Drugs , Pharmacovigilance , Commerce , Risk Assessment
11.
Am J Trop Med Hyg ; 107(1): 12-13, 2022 07 13.
Article in English | MEDLINE | ID: mdl-35895364

Subject(s)
Physicians , Refugees , Humans
12.
Am J Trop Med Hyg ; 107(2): 474-483, 2022 08 17.
Article in English | MEDLINE | ID: mdl-35895402

ABSTRACT

Antimicrobial resistance (AMR) is a public health emergency. There is insufficient information on AMR in the context of humanitarian settings. An understanding of behavioral and institutional-level factors can strengthen antimicrobial stewardship. This study used a semistructured questionnaire to assess both knowledge, attitudes, and practices (KAP) on antimicrobial use, resistance and stewardship, and options to improving prescribing, among prescribers at the Primary Healthcare facilities of the United Nations' Relief and Works Agency Jordan field office. Responses to the KAP questions were evaluated using the Capability, Opportunity, Motivation, Behavior (COM-B) framework and Bloom's cutoffs. For each framework component, Bloom's cutoffs and interpretations were as follows: ≥ 80%, "good"; 60-79%, "moderate"; and < 60%, "poor." Fourteen options to improve prescribing were each assessed using 5-point Likert scales from very unhelpful to very helpful, aggregated by helpful and very helpful and ranked as follows: > 90%, best/most acceptable; > 80-90%, acceptable; and 70-80% as maybe acceptable/good. The questionnaire response rate was 59% (37/63) with a completion rate of 92% (34/37). Aggregate scores for real knowledge on AMR was 97%; opportunity to improve prescribing 88%; and motivation 16%-participants did not believe that there was a connection between their prescribing and AMR or that they had a key role in helping control AMR. Good options (74% aggregate score) to improving prescribing were the availability of guidelines and resistance data. There was good knowledge of AMR and good opportunities, but poor motivation for rational prescribing or behavioral change. There is a clinical need for AMR data to promote rational antibiotic prescribing.


Subject(s)
Anti-Infective Agents , Humans , Jordan , Anti-Bacterial Agents/therapeutic use , Surveys and Questionnaires , Primary Health Care
13.
mSphere ; 6(6): e0077821, 2021 12 22.
Article in English | MEDLINE | ID: mdl-34787446

ABSTRACT

Resistance to third-generation cephalosporins among Gram-negative bacteria is a rapidly growing public health threat. Among the most commonly used third-generation cephalosporins is ceftriaxone. Bacterial exposure to sublethal or sub-MIC antibiotic concentrations occurs widely, from environmental residues to intermittently at the site of infection. Quality of ceftriaxone is also a concern, especially in low- and middle-income countries, with medicines having inappropriate active pharmaceutical ingredient (API) content or concentration. While focus has been largely on extended-spectrum ß-lactamases and high-level resistance, there are limited data on specific chromosomal mutations and other pathways that contribute to ceftriaxone resistance under these conditions. In this work, Escherichia coli cells were exposed to a broad range of sub-MICs of ceftriaxone and mutants were analyzed using whole-genome sequencing. Low-level ceftriaxone resistance emerged after as low as 10% MIC exposure, with the frequency of resistance development increasing with concentration. Genomic analyses of mutants revealed multiple genetic bases. Mutations were enriched in genes associated with porins (envZ, ompF, ompC, and ompR), efflux regulation (marR), and the outer membrane and metabolism (galU and pgm), but none were associated with the ampC ß-lactamase. We also observed selection of mgrB mutations. Notably, pleiotropic effects on motility and cell surface were selected for in multiple independent genes, which may have important consequences. Swift low-level resistance development after exposure to low ceftriaxone concentrations may result in reservoirs of bacteria with relevant mutations for survival and increased resistance. Thus, initiatives for broader surveillance of low-level antibiotic resistance and genomic resistance determinants should be pursued when resources are available. IMPORTANCE Ceftriaxone is a widely consumed antibiotic used to treat bacterial infections. Bacteria, however, are increasingly becoming resistant to ceftriaxone. Most work has focused on known mechanisms associated with high-level ceftriaxone resistance. However, bacteria are extensively exposed to low antibiotic concentrations, and there are limited data on the evolution of ceftriaxone resistance under these conditions. In this work, we observed that bacteria quickly developed low-level resistance due to both novel and previously described mutations in multiple different genes upon exposure to low ceftriaxone concentrations. Additionally, exposure also led to changes in motility and the cell surface, which can impact other processes associated with resistance and infection. Notably, low-level-resistant bacteria would be missed in the clinic, which uses set breakpoints. While they may require increased resources, this work supports continued initiatives for broader surveillance of low-level antibiotic resistance or their resistance determinants, which can serve as predictors of higher risk for clinical resistance.


Subject(s)
Anti-Bacterial Agents/pharmacology , Ceftriaxone/pharmacology , Drug Resistance, Multiple, Bacterial/genetics , Escherichia coli Infections/microbiology , Escherichia coli/drug effects , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Escherichia coli/enzymology , Escherichia coli/genetics , Escherichia coli Infections/drug therapy , Microbial Sensitivity Tests , Whole Genome Sequencing , beta-Lactamases/genetics , beta-Lactamases/metabolism
14.
Am J Trop Med Hyg ; 105(5): 1404-1412, 2021 08 23.
Article in English | MEDLINE | ID: mdl-34424858

ABSTRACT

Antimicrobial resistance (AMR), largely driven by irrational use of antimicrobials, is a global, multifaceted problem calling for a complete understanding of all contributory factors for effective containment. In conflict settings, war-wounds and malnutrition can combine with existing social determinants to increase demand for antibiotics, compounding irrational use. In this study, we focus on Yemen, a low-income country with active conflict for the last 5 years, and analyze the current status of awareness and stewardship efforts regarding AMR. We performed a survey of prescribers/physicians and pharmacists to describe perceptions of AMR prevalence, antibiotic use practices, and stewardship in Yemen, supported by a nonsystematic scoping literature review and a key informant interview. Participants (96%, N = 54) reported a perceived high AMR prevalence rate. Prescribers (74%, 20/27) reported pressure to prescribe broad-spectrum antibiotics. In the majority of cases (81%, 22/27), antimicrobial sensitivity tests (AST) were not performed to inform antibiotic choice. The main barrier to AST was cost. Most pharmacists (67%, 18/27) sold antibiotics without prescriptions. Amoxicillin (including amoxicillin-clavulanate) was the most-commonly prescribed (63%, 17/27) or dispensed (81%, 22/27) antibiotic. AST was rated the least important solution to AMR in Yemen. While there was awareness of a high AMR rate, stewardship is poor in Yemen. We note that barriers to the use of AST could be addressed through the deployment of reliable, affordable, quality rapid diagnostics, and AST kits. Compulsory continuing education emphasizing the use of AST to guide prescribing and patients' awareness programs could help avoid irrational use.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Antimicrobial Stewardship/statistics & numerical data , Bacterial Infections/drug therapy , Drug Resistance, Bacterial , Pharmacists/psychology , Physicians/psychology , Practice Patterns, Physicians'/statistics & numerical data , Adult , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Pharmacists/statistics & numerical data , Physicians/statistics & numerical data , Surveys and Questionnaires , Yemen
15.
mSystems ; 6(3): e0036021, 2021 Jun 29.
Article in English | MEDLINE | ID: mdl-34100640

ABSTRACT

Although wastewater and sewage systems are known to be significant reservoirs of antibiotic-resistant bacterial populations and periodic outbreaks of drug-resistant infection, there is little quantitative understanding of the drivers behind resistant population growth in these settings. In order to fill this gap in quantitative understanding of the development of antibiotic-resistant infections in wastewater, we have developed a mathematical model synthesizing many known drivers of antibiotic resistance in these settings to help predict the growth of resistant populations in different environmental scenarios. A number of these drivers of drug-resistant infection outbreak, including antibiotic residue concentration, antibiotic interaction, chromosomal mutation, and horizontal gene transfer, have not previously been integrated into a single computational model. We validated the outputs of the model with quantitative studies conducted on the eVOLVER continuous culture platform. Our integrated model shows that low levels of antibiotic residues present in wastewater can lead to increased development of resistant populations and that the dominant mechanism of resistance acquisition in these populations is horizontal gene transfer rather than acquisition of chromosomal mutations. Additionally, we found that synergistic antibiotics at low concentrations lead to increased resistant population growth. These findings, consistent with recent experimental and field studies, provide new quantitative knowledge on the evolution of antibiotic-resistant bacterial reservoirs, and the model developed herein can be adapted for use as a prediction tool in public health policy making, particularly in low-income settings where water sanitation issues remain widespread and disease outbreaks continue to undermine public health efforts. IMPORTANCE The rate at which antimicrobial resistance (AMR) has developed and spread throughout the world has increased in recent years, and according to the Review on Antimicrobial Resistance in 2014, it is suggested that the current rate will lead to AMR-related deaths of several million people by 2050 (Review on Antimicrobial Resistance, Tackling a Crisis for the Health and Wealth of Nations, 2014). One major reservoir of resistant bacterial populations that has been linked to outbreaks of drug-resistant bacterial infections but is not well understood is in wastewater settings, where antibiotic pollution is often present. Using ordinary differential equations incorporating several known drivers of resistance in wastewater, we find that interactions between antibiotic residues and horizontal gene transfer significantly affect the growth of resistant bacterial reservoirs.

16.
Am J Trop Med Hyg ; 104(4): 1265-1270, 2021 01 25.
Article in English | MEDLINE | ID: mdl-33534746

ABSTRACT

Pakistan is experiencing the first known outbreak of extensively drug-resistant (XDR) Salmonella enterica serotype Typhi (resistant to third-generation cephalosporins). The outbreak originated in Hyderabad in 2016 and spread throughout the Sindh Province. Whereas focus has remained on Sindh, the burden of XDR typhoid in Punjab, the most populous province, and the rest of the country is understudied. Using laboratory data from Shaukat Khanum Memorial Cancer Hospital and Research Centre in Lahore (Punjab Province) and its network of more than 100 collection centers across the country, we determined the frequency of blood culture-confirmed XDR typhoid cases from 2017 to 2019. We observed an increase in XDR typhoid cases in Punjab, with the percent of ceftriaxone resistance among Salmonella Typhi cases increasing from no cases in 2017, to 30% in 2018, and to 50% in 2019, with children bearing the largest burden. We also observed spread of XDR typhoid to the two other provinces in Pakistan. To assess prevailing knowledge and practices on XDR typhoid, we surveyed 321 frontline healthcare workers. Survey results suggested that inappropriate diagnostic tests and antibiotic practices may lead to underdiagnosis of XDR typhoid cases, and potentially drive resistance development and spread. Of those surveyed, only 43.6% had heard of XDR typhoid. Currently, serological tests are more routinely used over blood culture tests even though blood culture is imperative for a definitive diagnosis of typhoid fever. We recommend stronger liaisons between healthcare providers and diagnostic laboratories, and increased promotion of typhoid vaccination among healthcare workers and the general population.


Subject(s)
Anti-Bacterial Agents/pharmacology , Ceftriaxone/pharmacology , Drug Resistance, Multiple, Bacterial , Health Knowledge, Attitudes, Practice , Health Personnel/psychology , Salmonella enterica/drug effects , Typhoid Fever/epidemiology , Child, Preschool , Disease Outbreaks , Health Personnel/statistics & numerical data , Humans , Infant , Pakistan/epidemiology , Prevalence , Salmonella enterica/pathogenicity , Salmonella typhi/drug effects , Serogroup , Typhoid Fever/microbiology
17.
Sci Rep ; 10(1): 8754, 2020 05 29.
Article in English | MEDLINE | ID: mdl-32471975

ABSTRACT

To better combat bacterial antibiotic resistance, a growing global health threat, it is imperative to understand its drivers and underlying biological mechanisms. One potential driver of antibiotic resistance is exposure to sub-inhibitory concentrations of antibiotics. This occurs in both the environment and clinic, from agricultural contamination to incorrect dosing and usage of poor-quality medicines. To better understand this driver, we tested the effect of a broad range of ciprofloxacin concentrations on antibiotic resistance development in Escherichia coli. We observed the emergence of stable, low-level multi-drug resistance that was both time and concentration dependent. Furthermore, we identified a spectrum of single mutations in strains with resistant phenotypes, both previously described and novel. Low-level class-wide resistance, which often goes undetected in the clinic, may allow for bacterial survival and establishment of a reservoir for outbreaks of high-level antibiotic resistant infections.


Subject(s)
Ciprofloxacin/pharmacology , Drug Resistance, Multiple, Bacterial , Escherichia coli/drug effects , Base Sequence , Ciprofloxacin/administration & dosage , DNA, Bacterial/genetics , Dose-Response Relationship, Drug , Drug Resistance, Multiple, Bacterial/genetics , Escherichia coli/genetics , Microbial Sensitivity Tests , Selection, Genetic , Time Factors , Whole Genome Sequencing
18.
JAC Antimicrob Resist ; 2(3): dlaa068, 2020 Sep.
Article in English | MEDLINE | ID: mdl-34223024

ABSTRACT

BACKGROUND: Understanding social and scientific drivers of antibiotic resistance is critical to help preserve antibiotic efficacy. These drivers include exposure to subinhibitory antibiotic concentrations in the environment and clinic. OBJECTIVES: To summarize and quantify the relationship between subinhibitory fluoroquinolone exposure and antibiotic resistance and mutagenesis to better understand resistance patterns and mechanisms. METHODS: Following PRISMA guidelines, PubMed, Web of Science and Embase were searched for primary in vitro experimental studies on subinhibitory fluoroquinolone exposure and bacterial antibiotic resistance and mutagenesis, from earliest available dates through to 2018 without language limitation. A specifically developed non-weighted tool was used to assess risk of bias. RESULTS: Evidence from 62 eligible studies showed that subinhibitory fluoroquinolone exposure results in increased resistance to the selecting fluoroquinolone. Most increases in MIC were low (median minimum of 3.7-fold and median maximum of 32-fold) and may not be considered clinically relevant. Mechanistically, resistance is partly explained by target mutations but also changes in drug efflux. Collaterally, resistance to other fluoroquinolones and unrelated antibiotic classes also develops. The mean ± SD quality score for all studies was 2.6 ± 1.8 with a range of 0 (highest score) to 7 (lowest score). CONCLUSIONS: Low and moderate levels of resistance and efflux changes can create an opportunity for higher-level resistance or MDR. Future studies, to elucidate the genetic regulation of specific resistance mechanisms, and increased policies, including surveillance of low-level resistance changes or genomic surveillance of efflux pump genes and regulators, could serve as a predictor of MDR development.

19.
BMJ Open ; 9(10): e030747, 2019 10 30.
Article in English | MEDLINE | ID: mdl-31666265

ABSTRACT

INTRODUCTION: Antibiotic resistance (AR) is among the most pressing global health challenges. Fluoroquinolones are a clinically important group of antibiotics that have wide applicability in both humans and animals. While many drivers of AR are known, the impact of medicine quality on AR remains largely unknown. The aim of this review is to systematically evaluate the evidence of the impact of in vitro subinhibitory antibiotic exposure, a major tenet of substandard antibiotics, on the development of AR and mutagenesis, using fluoroquinolones as a case study. METHODS AND ANALYSIS: EMBASE, Web of Science and PubMed will be systematically searched for primary experimental in vitro studies, from earliest available dates within each database (1947, 1965 and 1966, respectively) through 2018, related to subinhibitory fluoroquinolone exposure and AR. A specifically developed non-weighted tool will be used to critically assess the evidence. Subgroup analyses will be performed for different variables and outcomes. ETHICS AND DISSEMINATION: Ethical approval is not required as no primary data are to be collected. The completed systematic review will be disseminated through conference meeting presentations and a peer-reviewed publication.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial/genetics , Fluoroquinolones/pharmacology , Mutagenesis , Bacteria/drug effects , Bacteria/genetics , Humans , Microbial Sensitivity Tests , Research Design , Systematic Reviews as Topic
20.
J Bacteriol ; 201(2)2019 01 15.
Article in English | MEDLINE | ID: mdl-30348832

ABSTRACT

Acinetobacter baumannii is a Gram-negative opportunistic pathogen that is known to survive harsh environmental conditions and is a leading cause of hospital-acquired infections. Specifically, multicellular communities (known as biofilms) of A. baumannii can withstand desiccation and survive on hospital surfaces and equipment. Biofilms are bacteria embedded in a self-produced extracellular matrix composed of proteins, sugars, and/or DNA. Bacteria in a biofilm are protected from environmental stresses, including antibiotics, which provides the bacteria with selective advantage for survival. Although some gene products are known to play roles in this developmental process in A. baumannii, mechanisms and signaling remain mostly unknown. Here, we find that Lon protease in A. baumannii affects biofilm development and has other important physiological roles, including motility and the cell envelope. Lon proteases are found in all domains of life, participating in regulatory processes and maintaining cellular homeostasis. These data reveal the importance of Lon protease in influencing key A. baumannii processes to survive stress and to maintain viability.IMPORTANCEAcinetobacter baumannii is an opportunistic pathogen and is a leading cause of hospital-acquired infections. A. baumannii is difficult to eradicate and to manage, because this bacterium is known to robustly survive desiccation and to quickly gain antibiotic resistance. We sought to investigate biofilm formation in A. baumannii, since much remains unknown about biofilm formation in this bacterium. Biofilms, which are multicellular communities of bacteria, are surface attached and difficult to eliminate from hospital equipment and implanted devices. Our research identifies multifaceted physiological roles for the conserved bacterial protease Lon in A. baumannii These roles include biofilm formation, motility, and viability. This work broadly affects and expands understanding of the biology of A. baumannii, which will permit us to find effective ways to eliminate the bacterium.


Subject(s)
Acinetobacter baumannii/enzymology , Acinetobacter baumannii/physiology , Biofilms/growth & development , Locomotion , Protease La/metabolism , Microbial Viability , Stress, Physiological
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