The use of biochemical tests to identify multiple insecticide resistance mechanisms in field-selected populations of Anopheles subpictus Grassi (Diptera: Culicidae)

1987 ◽  
Vol 77 (1) ◽  
pp. 57-66 ◽  
Author(s):  
J. Hemingway ◽  
K. G. I. Jayawardena ◽  
I. Weerasinghe ◽  
P. R. J. Herath
Keyword(s):  
Public Health ◽  
Broad Spectrum ◽  
Esterase Activity ◽  
Selection Pressure ◽  
Resistance Mechanisms ◽  
Mixed Function Oxidase ◽  
Biochemical Tests ◽  
Anopheles Subpictus ◽  
Organophosphate Resistance ◽  
Mixed Function Oxidase Activity

AbstractAnopheles subpictus Grassi in Sri Lanka is under selection pressure from both agricultural and public health insecticides. Agricultural selection pressure has produced larval specific carbamate resistance which appears to be correlated with high esterase activity. High esterase activity was found in both larvae and adults, but one of the larval elevated bands was not present in the adult, and two other adult bands were not found in the larvae. Broad spectrum organophosphate resistance was found in both the larvae and the adults and was associated with an increase in mixed-function oxidase activity. There was no evidence of an altered AChE mechanism in this population.

Pyrethroid and organophosphate resistance in the tobacco whitefly Bemisia tabaci (Homoptera: Aleyrodidae)

1995 ◽  
Vol 85 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Matthew Cahill ◽  
Frank J. Byrne ◽  
Kevin Gorman ◽  
Ian Denholm ◽  
Alan L. Devonshire
Keyword(s):  
Insecticide Resistance ◽  
Bemisia Tabaci ◽  
Esterase Activity ◽  
Selection Pressure ◽  
Susceptible Strain ◽  
Cross Resistance ◽  
Resistance Factors ◽  
Organophosphate Resistance ◽  
Tobacco Whitefly ◽  
General Esterase

AbstractEleven strains of Bemisia tabaci (Gennadius), including a laboratory susceptible strain, were bioassayed as adults with three organophosphorus (OP) insecticides, three pyrethroids and one OP/pyrethroid combination. The contemporary strains were from diverse geographical areas and hosts and included examples of the A-, B-, and non-B-biotypes. All recent collections were multi-resistant to these insecticides which have been used extensively for their control. The patterns of cross-resistance for the OPs were clear but less so for the pyrethroids. All populations that resisted profenofos and cypermethrin also resisted the combination of profenofos and cypermethrin. Although the importance of selection pressure on levels of resistance was not easily quantifiable the highly selected populations exhibited the highest levels of resistance. The significant within, as well as between, biotype variation in resistance factors clearly indicated that insecticide resistance and biotype were not directly related. The roles of acetylcholinesterase sensitivity and general esterase activity in resistance to OPs and pyrethroids are discussed.

Ultrastructure and Drug Metabolism in the Developing Guinea Pig

1973 ◽  
Vol 31 ◽  
pp. 538-539
Author(s):  
W. Kuenzig ◽  
M. Boublik ◽  
J.J. Kamm ◽  
J.J. Burns
Keyword(s):  
Guinea Pig ◽  
Metabolic Activity ◽  
Animal Species ◽  
Adult Animal ◽  
Smooth Endoplasmic Reticulum ◽  
Fetal Life ◽  
Mixed Function Oxidase ◽  
Cytochrome P 450 ◽  
Microsomal Mixed Function Oxidase ◽  
Mixed Function Oxidase Activity

Unlike a variety of other animal species, such as the rabbit, mouse or rat, the guinea pig has a relatively long gestation period and is a more fully developed animal at birth. Kuenzig et al. reported that drug metabolic activity which increases very slowly during fetal life, increases rapidly after birth. Hepatocytes of a 3-day old neonate metabolize drugs and reduce cytochrome P-450 at a rate comparable to that observed in the adult animal. Moreover the administration of drugs like phenobarbital to pregnant guinea pigs increases the microsomal mixed function oxidase activity already in the fetus.Drug metabolic activity is, generally, localized within the smooth endoplasmic reticulum (SER) of the hepatocyte.

scholarly journals Prevalence of methicillin-resistant Staphylococcus aureus and pattern of antimicrobial resistance in mastitis milk of cattle in Chitwan, Nepal

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Asmita Shrestha ◽  
Rebanta Kumar Bhattarai ◽  
Himal Luitel ◽  
Surendra Karki ◽  
Hom Bahadur Basnet
Keyword(s):  
Public Health ◽  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Subclinical Mastitis ◽  
World Health ◽  
Dairy Herds ◽  
Microbiological Analysis ◽  
Biochemical Tests ◽  
Methicillin Resistant ◽  
Milk Samples

Abstract Background The threat of methicillin-resistant Staphylococcus aureus (MRSA) exists globally and has been listed as a priority pathogen by the World Health Organization. One of the sources of MRSA emergence is livestock and its products, often raised in poor husbandry conditions. There are limited studies in Nepal to understand the prevalence of MRSA in dairy animals and its antimicrobial resistance (AMR) profile. A cross-sectional study was conducted in Chitwan, one of the major milk-producing districts of Nepal, from February 2018 to September 2019 to estimate the prevalence of MRSA in milk samples and its AMR profile. The collected milk samples (n = 460) were screened using the California Mastitis Test (CMT) and positive samples were subjected to microbiological analysis to isolate and identify S. aureus. Polymerase Chain Reaction (PCR) was used to identify the presence of the mecA gene and screen for MRSA. Results In total, 41.5% (191/460) of milk samples were positive in the CMT test. Out of 191 CMT positive milk samples, the biochemical tests showed that the prevalence of S. aureus was 15.2% (29/191). Among the 29 S. aureus isolates, 6.9% (2/29) were identified as MRSA based on the detection of a mecA gene. This indicates that that 1.05% (2/191) of mastitis milk samples had MRSA. The antibiotic sensitivity test showed that 75.9% (22/29) and 48.3% (14/29) S. aureus isolates were found to be sensitive to Cefazolin and Tetracycline respectively (48.3%), whereas 100% of the isolates were resistant to Ampicillin. In total 96.6% (28/29) of S. aureus isolates were multidrug-resistant (MDR). Conclusions This study revealed a high prevalence of S. aureus-mediated subclinical mastitis in dairy herds in Chitwan, Nepal, with a small proportion of it being MRSA carrying a mecA gene. This S. aureus, CoNS, and MRSA contaminated milk poses a public health risk due to the presence of a phenotype that is resistant to very commonly used antibiotics. It is suggested that dairy herds be screened for subclinical mastitis and treatments for the animals be based on antibiotic susceptibility tests to reduce the prevalence of AMR. Furthermore, future studies should focus on the Staphylococcus spp. to explore the antibiotic resistance genes in addition to the mecA gene to ensure public health.

scholarly journals Broad-Spectrum Antiviral Strategies and Nucleoside Analogues

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 667
Author(s):  
Robert J. Geraghty ◽  
Matthew T. Aliota ◽  
Laurent F. Bonnac
Keyword(s):  
Public Health ◽  
Severe Acute Respiratory Syndrome ◽  
Broad Spectrum ◽  
Vaccine Development ◽  
Fast Response ◽  
Mechanisms Of Action ◽  
Public Health Emergency ◽  
Nucleoside Analogues ◽  
The Family ◽  
Antiviral Nucleoside

The emergence or re-emergence of viruses with epidemic and/or pandemic potential, such as Ebola, Zika, Middle East Respiratory Syndrome (MERS-CoV), Severe Acute Respiratory Syndrome Coronavirus 1 and 2 (SARS and SARS-CoV-2) viruses, or new strains of influenza represents significant human health threats due to the absence of available treatments. Vaccines represent a key answer to control these viruses. However, in the case of a public health emergency, vaccine development, safety, and partial efficacy concerns may hinder their prompt deployment. Thus, developing broad-spectrum antiviral molecules for a fast response is essential to face an outbreak crisis as well as for bioweapon countermeasures. So far, broad-spectrum antivirals include two main categories: the family of drugs targeting the host-cell machinery essential for virus infection and replication, and the family of drugs directly targeting viruses. Among the molecules directly targeting viruses, nucleoside analogues form an essential class of broad-spectrum antiviral drugs. In this review, we will discuss the interest for broad-spectrum antiviral strategies and their limitations, with an emphasis on virus-targeted, broad-spectrum, antiviral nucleoside analogues and their mechanisms of action.

Framing Bacterial Genomics for Public Health(care)

2021 ◽  
Author(s):  
Alison Laufer Halpin ◽  
L. Clifford McDonald ◽  
Christopher A. Elkins
Keyword(s):  
Public Health ◽  
National Laboratory ◽  
Resistance Mechanisms ◽  
Public Health Care ◽  
Virulence Determinants ◽  
Top Down ◽  
Bottom Up ◽  
The Public ◽  
Bacterial Genomics ◽  
Healthcare Associated

Advancements in comparative genomics have generated significant interest in defining applications for healthcare-associated pathogens. Clinical microbiology, however, relies on increasingly automated platforms to quickly identify pathogens, resistance mechanisms, and therapy options within CLIA- and FDA-approved frameworks. Additionally, and most notably, healthcare-associated pathogens, especially those that are resistant to antibiotics, represent a diverse spectrum of genera harboring complex genetic targets including antibiotic, biocide, and virulence determinants that can be highly transmissible and, at least for antibiotic resistance, serve as potential targets for containment efforts. U.S. public health investments have focused on rapidly detecting outbreaks and emerging resistance in healthcare-associated pathogens using reference, culture-based, and molecular methods that are distributed, for example, across national laboratory network infrastructures. Herein we describe the public health applications of genomic science that are built from the top-down for broad surveillance, as well as the bottom-up, starting with identification of infections and infectious clusters. For healthcare-associated, including antimicrobial-resistant, pathogens, we propose a combination of top-down and bottom-up genomic approaches leveraged across the public health spectrum, from local infection control, to regional and national containment efforts, to national surveillance for understanding emerging strain ecology and fitness of healthcare pathogens.

PYRETHROID RESISTANCE IN PEAR PSYLLA, PSYLLA PYRICOLA FOERSTER (HOMOPTERA: PSYLLIDAE), AND SYNERGISM OF PYRETHROIDS WITH PIPERONYL BUTOXIDE

1989 ◽  
Vol 121 (3) ◽  
pp. 219-223 ◽  
Author(s):  
Everett C. Burts ◽  
Hugo E. van de Baan ◽  
Brian A. Croft
Keyword(s):  
Oxidase Activity ◽  
Pyrethroid Resistance ◽  
Cyano Group ◽  
Piperonyl Butoxide ◽  
Mixed Function Oxidase ◽  
Pear Psylla ◽  
Mixed Function Oxidase Activity

AbstractAdult pear psylla, Psylla pyricola Foerster, from commercial pear orchards near Wenatchee, WA, were tested using a slide-dip technique for susceptibility to fenvalerate over a 5-year period from 1984 to 1988. Results were compared with those from similar tests using psyllids from an unexposed population near Corvallis, OR. During 5 years, resistance of adults to fenvalerate increased by 16- to 32-fold at Wenatchee while that of the Corvallis population did not change. In 1988, tests with five pyrethroids and pyrethroid – piperonyl butoxide combinations indicated that pear psylla adults also were resistant to permethrin and flucythrinate but not to fenpropathrin or cyfluthrin which contain a cyano group that reduces their susceptibility to oxidase metabolism. Piperonyl butoxide synergism was proportional to the level of resistance, indicating that resistance is probably due to increased mixed function oxidase activity. Implications of this study to control of post-diapause winter form adults in commercial pear orchards is discussed.

scholarly journals Mechanisms of Antimicrobial Resistance in ESKAPE Pathogens

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Sirijan Santajit ◽  
Nitaya Indrawattana
Keyword(s):  
Public Health ◽  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Global Public Health ◽  
Drug Usage ◽  
Inappropriate Use ◽  
Public Health Challenges ◽  
Eskape Pathogens

The ESKAPE pathogens (Enterococcus faecium,Staphylococcus aureus,Klebsiella pneumoniae,Acinetobacter baumannii,Pseudomonas aeruginosa, andEnterobacterspecies) are the leading cause of nosocomial infections throughout the world. Most of them are multidrug resistant isolates, which is one of the greatest challenges in clinical practice. Multidrug resistance is amongst the top three threats to global public health and is usually caused by excessive drug usage or prescription, inappropriate use of antimicrobials, and substandard pharmaceuticals. Understanding the resistance mechanisms of these bacteria is crucial for the development of novel antimicrobial agents or other alternative tools to combat these public health challenges. Greater mechanistic understanding would also aid in the prediction of underlying or even unknown mechanisms of resistance, which could be applied to other emerging multidrug resistant pathogens. In this review, we summarize the known antimicrobial resistance mechanisms of ESKAPE pathogens.

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