Comprehensive Guide to Antimicrobials and Disinfection in Veterinary Medicine

Antimicrobials

Kill or inhibit the growth of microorganisms.

Antibiotic

A type of antimicrobial used interchangeably with antimicrobials.

Cidal

The suffix meaning to kill.

Static

The suffix meaning to inhibit replication, but not kill.

Goals of antimicrobials

The goal is to kill or inhibit the growth of microorganisms without killing the host (the animal).

Minimum inhibitory concentration (MIC)

A measurement of the bacteria's susceptibility to an antimicrobial; the lowest amount of a drug that is needed to inhibit growth of a bacteria.

Sensitive

If bacteria can be killed by a drug and it is within a tolerable amount by the animal.

Resistant

If concentrations of the drug would be too high for the animal to tolerate to kill the bacteria.

Culture and sensitivity test

A sample from the infected site should be sent off to a lab to perform this test.

Example of MIC

A strain of Staphylococcus bacteria may be highly sensitive to the antibiotic gentamicin BUT be quite resistant to penicillin.

Gram Positive and Negative

Categories of bacteria that antimicrobials can target.

Classes of Antimicrobials

Includes Antibiotic, Antifungal, Antiviral, Antiprotozoal, Antiparasitic.

Narrow-spectrum antibiotic

Drugs that act specifically on the gram-positive family or specifically on the gram-negative family of bacteria.

Broad-spectrum antibiotic

Drugs that act on both gram-positive and gram-negative bacteria.

Mechanisms of Antibiotics

Include inhibition of cell wall synthesis, damage to the cell membrane, inhibition of protein synthesis, interference with metabolism, and impairment of nucleic acids production.

Antibiotic Resistance

Occurs when bacteria change in some way that reduces or eliminates the effectiveness of the agent used to treat or prevent the infection.

Resistance

When a bacteria develops the ability to survive in the presence of an antimicrobial.

Antibiotic residues

The presence of a chemical or its metabolites in animal tissues or food products.

Concerns of Antibiotic Residues

Food-producing animals are of great concern because even low levels of these residues can cause allergic reactions in people or can produce resistant bacteria that can be transferred to the people who consume these products.

Broad Spectrum Antibiotic

An antibiotic that is effective against a wide range of infectious microorganisms.

Narrow Spectrum Antibiotic

Effective against only a limited range of organisms.

Penicillin's

One of the most commonly used groups of antimicrobials.

➢ Penicillin-G
➢ Ampicillin
➢ Amoxicillin

Aminoglycosides

➢ Bactericidal
➢ Work well against aerobic bacteria
➢ Not very well on anaerobic bacteria
➢ Work well on open skin
➢ Eliminated by the kidneys

\➢ Gentamicin
➢ Amikacin
➢ Neomycin
➢ Streptomycin
➢ Tobramycin

Clavamox

medicine that’s good for the bladder

Cephalosporins

➢ First generations of cephalosporins
⚫ work well on gram positive bacteria
➢ Second and third generations
⚫ work well on gram negative bacteria
➢ They are bactericidal
➢ They act very much like penicillin's

drugs:

➢ (Cefa-Tabs, Cefa-Drops)
➢ (Naxcel and Excenel)
➢ (Simplicef)
➢ cephalexin (Keflex

Tetracyclines

Bacteriostatic antibiotics mainly used for rickettsial infections. causes yellow permanent teeth 

Bacitracin

Primarily against gram positive bacteria and popular as topical medication for skin, mucous membranes, and ocular surfaces.
Feed additive to control intestinal
pathogens in large animals
➢ Caution-toxic to kidney

Clavulanic acid

Added to amoxicillin to produce Clavamox, helping with bacteria that are resistant to amoxicillin alone.

Precautions with penicillin's

Allergic reactions are the most common, with symptoms ranging from a rash to anaphylactic shock.

Cephalosporins Precautions

A potential for allergic reactions exists, not as severe as penicillin.

Aminoglycosides Precautions

Nephrotoxic and ototoxic, with potential for deafness or loss of equilibrium.

Tetracyclines Precautions

Bind to calcium and can cause yellow teeth if given while the teeth are developing.

Penicillin-G

A type of penicillin used in treatment.

Ampicillin

A type of penicillin used in treatment.

Amoxicillin

A type of penicillin used in treatment.

Gentamicin

An aminoglycoside antibiotic.

Amikacin

An aminoglycoside antibiotic.

Neomycin

An aminoglycoside antibiotic.

Streptomycin

An aminoglycoside antibiotic.

Tobramycin

An aminoglycoside antibiotic.

Superinfections

Can occur in the gut due to the use of tetracyclines.

Chloramphenicol

Bacteriostatic; can be bactericidal at higher doses.

Macrolides

Bacteriostatic; often used as penicillin substitutes since they act very similarly.

Erythromycin

Zithromax for humans.

Tylosin

Tylan.

Lincosamides

Lincomycin (Lincocin) and clindamycin (Antirobe).

Sulfonamides

Not used as an antimicrobial; used for its anti-inflammatory action on the intestines.

KCS

Keratoconjunctivitis sicca, a condition caused by sulfonamides in dogs.

Pruritus

Itching that can be caused by sulfonamides.

Facial swelling

A potential allergic reaction to sulfonamides.

Hives

A skin reaction that can occur with sulfonamide use.

Allergic reactions

Reactions that can occur in large breeds and people due to sulfonamides.

Liver dysfunction

A possible side effect of sulfonamide use.

Thrombocytopenia

A condition that can occur as a side effect of sulfonamides.

Leukopenia

A decrease in white blood cells that can result from sulfonamide use.

Anemia

A potential side effect of sulfonamide use.

Crystalluria

The presence of crystals in urine, a possible effect of sulfonamides.

Salivation in cats

A side effect associated with sulfonamide use.

Quinolones

Also called fluoroquinolones, they are bactericidal antibiotics effective against gram-negative and gram-positive bacteria.

Enrofloxacin

A type of quinolone antibiotic, also known as Baytril.

Marbofloxacin

A type of quinolone antibiotic, also known as Zeniquin.

Orbifloxacin

A type of quinolone antibiotic, also known as Orbax.

Ciprofloxacin

A type of quinolone antibiotic.

Cartilage damage

A potential risk of using quinolones in growing animals.

Sucralfate

Quinolones should not be used within 4 hours of this medication.

Nitrofuran's

A class of antibiotics used to treat urinary tract infections and kennel cough.

Furazolidone

A type of nitrofuran antibiotic.

Nitrofurazone

A type of nitrofuran antibiotic.

Nitroimidazone

A class of antibiotics used to treat Giardia, Trichomonas, amoebiasis, and anaerobic bacteria.

Metronidazole

Also known as Flagyl, it is the drug of choice for canine diarrhea.

Neurologic side effects

Possible effects of nitroimidazone, including loss of balance and seizures.

Rifampin

An antibiotic that can be used for some staph and fungal infections.

Antifungal

Medications that target fungal infections, divided into mold and yeast groups.

Amphotericin B

An antifungal effective against most deep mycoses but can cause nephrotoxicosis.

Azoles

A class of antifungals that includes ketoconazole, itraconazole, and fluconazole.

Griseofulvin

An antifungal used to treat ringworm, toxic in cats, and teratogenic.

Disinfection

The destruction of pathogenic microorganisms to prevent disease spread.

Nosocomial infections

Infections acquired during a hospital stay, often involving resistant bacteria.

Germicide

a chemical that kills microorganisms

Bactericidal

a chemical that kills bacteria

Chloramphenicol

used for eye and CNS problems

nystagmus 

shaking of the eyes

Virucidal

a chemical that kills viruses

Fungicidal

a chemical that kills fungi

Sporicidal

a chemical that kills endospores, which are especially resistant to chemicals

Tuberculocidal

a chemical that kills Mycobacterium tuberculosis

Antiseptics

kill or inhibit growth of microorganisms on living tissue

Disinfectants

do the same thing just on inanimate objects

Sanitizers

reduce the number of microbes to a safe level

Sterilizers

kill all microorganisms

Factors for selecting disinfectant

1) The type of microorganism 2) The environment in which the disinfectant will be used 3) The characteristics of the disinfectant

Phenols

in a lot of products

Lysol

a product containing phenols

Pine oil

a product containing phenols

Quaternary ammonium compounds

not very effective against anything and become ineffective totally with organic material, soap, and hard water

Aldehydes

Glutaraldehyde-kill fungi and bacteria within a few minutes and endospores in about three hours

Glutaraldehyde

used for a chemical sterilization (takes 15 minutes)

Formaldehyde

extreme toxicity and classification as a carcinogen

Alcohols

ethyl and isopropyl are the most common types of antiseptics used

Halogens

Iodine commonly used as topical antiseptics