antimicrobial resistance&water Flashcards
when did Fleming discover penicillin
1928
when were sulfonamides introduced and by who
1935; ehrlich
when was MRSA first noted
1968
what are some resistant bacteria
multi-drug resistant mycobacterium tuberculosis; penicillin resistant stretococcus pneumoniae; vancomycin-resistant enterococci (VRE); carbapenem resistant enterobacteriaciae (CRE)
what are the 4 important principles of antimicrobial resistance
- antimicrobial use SELECTS for resistant populations; 2. organisms resistant to one antimicrobial often become resistant to MULTIPLE drugs; 3. antimicrobial resistance in one area will eventually appear in OTHER areas; 4. once antimicrobial resistance appears, it is UNLIKELY to decline spontaneously
what are the 2 main issues for antimicrobial resistance
preservation of antimicrobials for human medicine/health; preservation of antimicrobials for vet med and animal health
what is the driving force for antimicrobial resistance
imprudent use of antimicrobials
what is imprudent use of antimicrobials
use of antimicrobials when not needed; use of wrong antimicrobial; use of broadspectrum antimicrobial when a narrowspectrum will work; wrong dosage or dosing interval
what is imprudent use of antimicrobials
use of antimicrobials when not needed; use of wrong antimicrobial; use of broadspectrum antimicrobial when a narrowspectrum will work; wrong dosage or dosing interval
4 uses of antimicrobials in veterinary medicine
therapy, metaphylaxis, prophylaxis, growth promotion/feed efficiency
what does therapy consist of
injection, in-feed, in-water, individual or group
what does metaphylaxis consist of
same as therapy but is done when one animal is sick to pre-emptively treat the others
what does prophylaxis consist of
in-feed, GROUP; treating entire group pre-emptively
which obligations must veterinarians balance?
oath to protect animal health and promote public health at the same time
which obligations must veterinarians balance?
oath to protect animal health and promote public health at the same time
what are current activities for reducing AMR
chief veterinary officers (prescription only, surveillance/data collection), senate hearings, user pay initiatives, phasing out growth promotants, targeted reduction of use
what is the Canadian experience with emerging antimicrobial resistance
salmonella heidelberg resistant to 3rd generation ceftiofur
why is S. heidelberg resistance a problem
frequent pathogen in humans that can be invasive (causing sepsis); limited treatment options for children and pregnant women
why are the treatment options limited for children and pregnant women if they are infected with ceftiofur resistant S. heidelberg
can’t use fluoroquinolones in them
what is one of the single biggest drivers of infectious disease
water quality
what types of diseases are related to water
water-borne, water-washed, water-based, water-vector/related
water-borne diseases
disease caused by ingestion of water contaminated by human or animal excrement that contains pathogenic organisms
water-washed diseases
disease caused by poor personal hygiene, skin and eye contact with contaminated water
water-based diseases
disease caused by parasites found in intermediate organisms living in contaminated water
water-vector/related diseases
disease caused by insect vectors that breed or feed near contaminated water
some important water-borne pathogens
E. coli, campylobacter, vibrio cholera, cryptosporidium
factors in re-emergence of zoonotic pathogens
changing patterns of water use, population factors, increased travel/recreational activities, water scarcity, climate change, severe weather events, conflicts/disasters, increased urbinization, increased demand for animal protein and fresh vegetables, increased antibiotic use, increasingly concentrated animal husbandry practices, density of domestic pets, international trade patterns, ecosystem disturbance
factors in re-emergence of zoonotic pathogens
changing patterns of water use, population factors, increased travel/recreational activities, water scarcity, climate change, severe weather events, conflicts/disasters, increased urbinization, increased demand for animal protein and fresh vegetables, increased antibiotic use, increasingly concentrated animal husbandry practices, density of domestic pets, international trade patterns, ecosystem disturbance
what was the water contaminated with in Walkerton
E.coli (VTEC) and campylobacter
what is pulsenet canada used for
food and waterborne disease outbreaks
how long can E. coli 0157 survive in soil
56-130 days
how long does E. coli 0157 survive in a slurry of manure
10 days
how can you minimize risk from animal waste
farm biosecurity; vaccination; waste treatment before release
what are examples of waste treatment that can be done on farm
composting, air drying, lagoon/storage, digestion (anaerobic or aerobic)
what are examples of waste treatment that can be done on farm
composting, air drying, lagoon/storage, digestion (anaerobic or aerobic)
how is cryptosporidium parvum (bovine) transmitted
from human to cattle and cattle to human
how is cryptosporidium hominus transmitted
human to human (NOT human to cattle)
how is cryptosporidium spread
water contaminated with feces of infected person or animal feces; contact with infected person
what is the primary means to remove cryptosporidium from water
physical removal by filtration
why can cryptosporidium only be removed by physical filtration
oocysts are resistant to chemical disinfection
why can cryptosporidium only be removed by physical filtration
oocysts are resistant to chemical disinfection
what does cryptosporidium cause
asymptomatic infections and symptomatic infection (profuse watery diarrhea, cramping, abdominal pain)
how long does cryptosporidiosis last
self-limiting and usually lasts 3-4 days (no longer than 30d)
infective dose of cryptosporidium
10 oocysts
when are crypto oocysts infectious
immediately upon excretion
when does shedding of crypto oocysts stop
usually 2 weeks after symptoms end
how long do crypto oocysts remain infective outside the body
2 to 6 months in a moist environment
most common sources of crypto infection
recreational water (ex. water parks), contact with livestock, drinking water, and person to person transmission
factors that contribute to risks of crypto water-borne outbreaks
small oocyst size, wide range of host specificity, close associations between animals/humans, large numbers of oocysts excreted, low infective dose, oocyst resistance to chlorine, infectious upon excretion
what are characteristics of water-borne outbreaks
high proportion of population affected, illness experienced through all age groups, affected persons have epidemiological link to one community/water source
general water-outbreak causes
inadequate disinfection, cross-connections, inadequate control over treatment process (esp. filtration), interruption in treatment, disruption in service, infiltration of polluted water/sewage
general water-outbreak causes
inadequate disinfection, cross-connections, inadequate control over treatment process (esp. filtration), interruption in treatment, disruption in service, infiltration of polluted water/sewage
information for waterborne outbreak investigation
water plant process monitoring data, public health and clinical lab results, physician visits for gastroenteritis, school/daycare absences, nursing home diarrheal rates, sales of anti-diarrheal drugs
what is the indicator organism used for water testing
E. coli
why is E. coli used as an indicator organism
present in large numbers in mammal feces, readily detectable, doesn’t grown in natural water, persistence and removal from water are similar to other pathogens
criteria for water testing
E. coli must not be detectable in any 100mL sample
what does water testing frequency depend on
population size
what indicator organism is used in marine water
enterococci
what indicator organism is used in marine water
enterococci
which infectious organisms are not routinely tested for
giardia and crypto
