Victoria Alday-Sanz, D.V.M., M.Sc., Ph.D.

Member of the OIE ad hoc group on Antimicrobials in Aquatic Animals

Peter Smith, Chair (Academician)

Jennifer Matysczak (FDA)

Donald Prater (FDA)

Gerard Moulin (National Agency for Veterinary Medicinal Products, France)

Celia Pitogo (Aquaculture producer, Phillipines/Brunei)

Victoria Alday (Aquaculture producer)

OIE Staff

Chapter 6.3.

Principles for responsible and prudent use of antimicrobial agents in aquatic animals

Chapter 6.4.

Monitoring of the quantities and usage patterns of antimicrobial agents used in aquatic animals

Chapter 6.5.

Development and harmonisation of national antimicrobial resistance surveillance and monitoring programmes for aquatic animals

It defines the responsabilities of: The Competent Authorities

The veterinary pharmaceutical industry

The wholesale and retail distributor

The veterinarians and other aquatic animal health professionals

The aquatic animal producers

Specifying the terms of the authorization and providing the appropriate information through labeling or other means

Developing up-to-date guidelines on data requirements for evaluation of antimicrobial agent applications

Promoting good animal husbandry practices, vaccination policies and development of animal health care at the farm level, together with veterinarians (p/v)

Granting marketing authorizations when criteria of quality, efficacy and safety are met.

Responsabilities of the Competent Authorities (1)

Monitor the performance of susceptibility testing from laboratories and disseminating information on trends in antimicrobial resistance collected during surveillance programmes to veterinarians (p/v) and should.

Providing effective procedures for the safe collection and destruction of unused or out-of-date antimicrobial agents.

Providing information requested by the CA:

on the quality, efficacy and safety of antimicrobial agents

Covering pre- and post- marketing phases, including manufacturing, sale, importation, labelling, advertising and pharmacovigilance.

amount of antimicrobial agents marketed.

Should ensure that the advertising antimicrobial agents to the aquatic animal producer is discouraged.

Responsabilities of the veterinary pharmaceutical industry

Compliance with the relevant legislation

Availability of information for the appropriate use and disposal with each distributed product

Maintaining and disposing of the product according to the manufacturer recommendations.

Promote biosecurity programs to minimise the need for antimicrobial use

Only prescribe, dispense or administer antimicrobials for aquatic animals under their care

Reach a diagnosis before prescription and analyse environmental conditions for primary cause

If treatment is deemed necessary it should be initiated as soon as possible and only later confirm susceptibility of the agent

Results of all susceptibility tests should be available to the CA

Responsabilities of the veterinarians and other aquatic animal health professionals (1)

Indicating the treatment regime: dose, duration, withdrawal period and amount to be delivered

Using of extra-label/off-label in conformity with the legislation.

Revise farm records to ensure compliance with their directions and evaluate the efficacy of treatment

Records on the use should be kept and lack of efficacy should be reported to the CA

Implementing biosecurity programmes: culture strategies, vaccination, pathogen detection, maintenance of good water, etc…

Using antimicrobials only on the prescription of a veterinarian (p/v) and following his/her directions

Properly storaged, handling and disposal

Keeping records of antimicrobial agents used, bacteriological and susceptibility tests and make such records available to the veterinarian (p/v)

Informing of recurrent disease problems and lack of efficacy of antimicrobial agent treatment regimes.

This information is crucial to carry out: Risk analysis: identification of trends in the use and the

association with resistance

Risk management: evaluating the effectiveness of use and mitigation strategies

Development of an standard monitoring system (human, agriculture and aquaculture): quantities, class, route, diagnosis

Should include related data to interpreter the use of antimicrobial agents (system, developmental stage, culture parameters, dosage, duration, etc…)

Establish data on the prevalence of resistance

Collect information on antimicrobial resistance trends

Explore relationship resistance in aquatic animal microorganisms and the use of antimicrobial agents;

Detect the emergence of antimicrobial resistance mechanisms;

Provide recommendations on human health and aquatic animal health policies and programmes

Etc…

For microorganisms that infect aquatic animals

For microorganisms in or on aquatic animal products intended for human consumption

Selection of microorganism: primary pathogen, commonly encountered, not from same epizootic

Method: MIC or disc diffusion (standard methods if available: CSLI)

Laboratory quality control

Choice of all major antimicrobial groups

Data publication

Interpretation both for epidemiological and clinical purposes

Chapter 6.7 of the OIE Terrestrial Animal Health Code

Intestinal microflora should only be considered when there is evidence that these are resident for long enough (mostly transient)

All sources of contamination should be taken into account (manure or molasses)

Minimum species: Salmonella spp.;

Vibrio parahaemolyticus;

Listeria monocytogenes

Tecnical Advisor for the National Prawn

Company

Director for Aquatic Animal Health, PESCANOVA

Victoria Alday-Sanz, D.V.M., M.Sc., Ph.D.

Never faced a clinical antimicrobial resistance problem in aquaculture production

Antibiotics in aquaculture are tools for very specific situations: Development of culture procedures for new species

Primary pathogens (intracelllular bacteria)

Diversity

Shrimp production

Backyard hatchery

Industrial scale

Countries in the early stages of

commercial aquaculture (Africa), are

putting aquaculture development at

the tope of their agendas (key

player) for food and job security

Lack of knowledge on aquaculture, except in Asia

Differences in legislation

Huge differences in enforcement

Shortage of tools for sanitary management: antibiotics, desinfectans, pesticides, etc… (contrast with veterinary and human medicine)

Insufficient Market Authorizations: expensive process

Aquaculture small market: does not justify the investment

Many species, many diseases, many culture conditions…

OTC most used treatment

Species % Resp.

Shrimp 56%

Salmon 50%

Trout 84%

Tilapia 56%

Panga 65%

Carp 51%

Marine 57%

Catfish 90%

Number of substances reported

Species Number of products N treat N prophyl

Shrimp 5-15 3-7 3-8

Salmon 3-18 3-14 2-4

Trout 8-17 6-13 3-8

Tilapia 6-18 4-10 2-10

Panga 8-13 6-8 5-7

Carp 7-17 5-9 2-8

Marine 4-14 4-12 2-5

Catfish 11-18 6-11 4-7

For several species emphasis on treating!

Have not generated enough information on:

Pharmacodynamics

Pharmacokinetics

Antimicrobial interaction with the environment

top coating?

Fate of the antimicrobials in the environment

Requiere capacity building: On legislation

Product: use, risks and handling

Insufficient aquaculture professionals

A lab result is not a diagnosis

Need to follow up production

Need environmental data and management procedures

Bacterial and parasitic diseases are often linked to a primary cause: stress

Antibiotics are only tools, rarely solutions

Inmediate use of antimicrobials on identification needed: do not wait for susceptibility test results

If no clinical change in 48-72h, change antibiotic

Need to respect legislation particularly small farmers (education? inspections?)

Cost of authorised products versus active compounds

Good management practices:

Healthy animals do not get sick!!

Capacity building

Need for biosecurity plans for each facility

Reduce economic impact of diseases

Integrated into the production practices (SOPs)

but what about the RELEASE into the

environment of prudently used antimicrobials?

Little is known

It has been suggested that antibiotics have been produced for over 500million years (Baltz 2008)

Antibiotics are naturally produced by some species of bacteria and fungi (they encode resistance to those specific antibiotics)

Resistance genes existed long before we increased selection preassure

Antibiotics were turned into pharmaceuticals (x00.000tns/year)-disruption of equilibrium?

Heberer 2002

Antibiotics and other pharmaceuticals are often excreted unchanged and released into municipal water sewage system

B-lactams, quinolones or sulphonamides are not easily biodegradable (Al-Ahmad 1999; Kumerer 2000; Ingerslev 2000)

Sorption to the sludge: Quinolones, sulphonamides and tetracyclines are sorbed: 70-90% was re-extractable (30% of sludge is used as manure in Germany) Kumerer 2003. Some may be deactivated depending on the composition of the sediment

A proportion of antibiotics are not broken down in STPs and are released into the environment

Hospitals Antibiotic concentration in hospital effluents are of

the same order of magnitude as the minimum inhibitory concentrations for susceptible pathogenic bacteria (Kummerer and Henninger 2003)

Ciprofloxacin up to 124ug/L (Hartman 1998)

Ampicillin up to 80ug/L (Kumerer 2004)

The dilutions of hospital effluents by municipal sewage will lower the concentration only moderately as it also contains antibiotics and household disinfectants

Verlicchi

2010

Verlicchi 2010

Mixture of antibiotics may have a synergistic or antagonistic effect

Synthetic or semisynthetic antibiotics are often more stable and not biodegradable by bacteria

Biodegradation in STPs: not a reliable removal of antibiotics (Kumerer 2003)

Cyclosporin A: months to degrade in soil

Sarafloxacin: 90% active after 80 days in soil

Treatment of dewatered sludge with heat did not fully eliminate norfloxacin or ciprofloxacin (Lindberg 2007)

Conventional methods are innefective (biological processes, filtration, coagulation, flocculationa and sedimentation)

Combination of methods might be required: advance oxidation, adsorption, membrane processes, ozonation…

Most medical compounds are only partially metabolized by patients and are discharged into hospital sewage or municipal waste water to the STPs. The pass through the STP and are released into the environment

It is assumed that hospital are the most important source for the input of resistant bacteria into municipal waste water. However, consumption of antibiotics: UK: 95% community

USA and Germany 75% community

(Schuster 2008)

Hospital in western europe contribut to 1% municipal sewage, Hospitals might not be the main source of resistant

bacteria, but might be for multi-resistant bacteria

Human sewage comprises both antibiotic residues and antibiotic resistant bacteria (resistant determinants)

Waste water treatment plants are considered reservoirs of antibiotic resistance in the environment (Gallert 2005; Ferreira da Silva 2006; Goñi-Urriza 2000; Baquero 2008; Kummerer 2009; Martinez 2009; Servais 2009)

The transfer of resistant genes, as well as resistant bacteria, is favoured by the presence of antibiotics over a long period and at subtherapeutic concentrations (Salyers 1995; Ohlsen 1998)

Waste water treatment process has been reported to be a route for disseminating antimicrobial resistant bacteria into the environment (Kim 2007)

Sewage isolates had higher antimicrobial resistance rates than clinical isolates from the same hospital (Yang 2009)

Assumption: No growth=death of bacteria

Response to environmental factors: starvation, temperature, oxygen, light (Olivier 2000)

Bactericidal treatments might induce this VBNC state (milk pasteurization, chlorination) (Olivier et al 2005)

Between 90 and 99% of marine bacteria are in VBNC (Colwell; Hirashi 1998)

The ¨resuscitate¨ to culturable state mantaining virulence and plasmids

Table 1. Bacteria Described to Enter the

VBNC State (Oliver 2005) Aeromonas salmonicida Lactobacillus plantarum Serratia marcescens Agrobacterium tumefaciens Lactococcus lactis Shigella dysenteriae Alcaligenes eutrophus Legionella pneumophila S. flexneri Aquaspirillum sp. Listeria monocytogenes S. sonnei Burkholderia cepacia Micrococcus flavus Sinorhizobium meliloti B. pseudomallei M. luteus Streptococcus faecalis Campylobacter coli M. varians Tenacibaculum sp. C. jejuni Mycobacterium tuberculosis Vibrio anguillarum M. Smegmatis C. lari Pasteurella piscida V. campbellii Cytophaga allerginae Pseudomonas aeruginosa V. cholerae Enterobacter aerogenes P. fluorescens V. fischeri E. cloacae P. putida V. harveyi Enterococcus faecalis P. syringae V. mimicus E. hirae Ralstonia solanacearum V. natriegens E. faecium Rhizobium leguminosarum V. parahaemolyticus Escherichia coli (including EHEC) R. meliloti V. proteolytica Francisella tularensis Rhodococcus rhodochrous V. shiloi Helicobacter pylori Salmonella enteritidis V. vulnificus (types 1&2) Klebsiella aerogenes S. typhi Xanthomonas campestris K. pneumoniae S. typhimurium K. planticola

While it could be questionable that the presence of antibiotics in the environment leads to an increase in resistance

The input of resistant bacteria from human and veterinary sources are the main contributors to resistance in the environment

Conclusion

Prudent use of antimicrobial

Proper disposal of unused antimicrobials

Development of new antibiotics easily biodegradable

Control of the release of:

Antimicrobials

Resistant bacteria and resistant genes

Effect of subclinical doses present in the environment

On antibiotic resistance development understanding

Resistant genes spread in nature

Different source of the different resistance found in the environment

Time scale for antibiotics to inactivate in the environment