Microbial Contamination: Historical and Types

Historical Context of Microbial Contamination

• Latta introduced the initial intravenous therapy using salt, bicarbonate, and water in 1831 to treat cholera.
• Louis Pasteur conducted experiments in 1860 that explored the relationship between germs and disease.
• In 1847, Semmelweis found that hand disinfection in obstetrical clinics could drastically cut incidence of puerperal fever.
• Robert Koch founded modern bacteriology between 1880 and 1910.

Types of Microorganisms as Contaminants

• Microorganisms can cause disease and spoil pharmaceutical products.
• Common contaminant types include fungal cells/spores, yeast, protozoa, viral particulates, and bacterial cells/spores.
• Fungal cells/spores are eukaryotes that are free-living or parasitic, often facultative.
• Similarly, yeasts and protozoa are eukaryotic, free-living or parasitic, often facultative, and not obligate parasites.
• Viral particulates are obligate intracellular parasites ranging from 20-300 nm with a nucleic acid core inside a protein capsid.
• Bacterial cells/spores are prokaryotic and a primary concern in pharmaceutical microbiology.

Cell Wall Structure

• Gram-positive cell walls are made of peptidoglycan, teichoic acid polymers, and a cytoplasmic membrane.
• Gram-negative cell walls contain lipopolysaccharide, lipoprotein, porin, phospholipid, periplasmic space, peptidoglycan, and a cytoplasmic membrane.

Dangers and Infections

• Microbial contamination can lead to serious infections and diseases.
• These diseases include bacterial meningitis caused by Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Streptococcus agalactiae, and Listeria monocytogenes.
• Microbial causes of Otitis media can include are Streptococcus pneumoniae. Pneumonia caused by Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila, and Mycobacterium tuberculosis.
• Additionally, contamination may lead to skin infections such as Staphylococcus aureus, Streptococcus pyogenes, and Pseudomonas aeruginosa.
• Sexually transmitted diseases like Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum, Ureaplasma urealyticum, and Haemophilus ducreyi can also occur.
• Other potential infections include eye infections, sinusitis, upper respiratory tract infections and gastritis.
• Food poisoning can result from contamination by Campylobacter jejuni, Salmonella, Shigella, Clostridium, Staphylococcus aureus, and Escherichia coli.
• Urinary tract infections may be caused by Escherichia coli, other Enterobacteriaceae, Staphylococcus saprophyticus, and Pseudomonas aeruginosa.

Pyrogens and Endotoxins

• Pyrogens are substances inducing fever, either internally or externally.
• Endotoxins, associated with Gram-negative bacteria, are examples of pyrogens recognized by the immune system.
• All pyrogens are not endotoxins, and bacterial cells can be pyrogenic even when dead or fragmented.

Consequences of Contamination

• A Massachusetts firm was linked to a US meningitis outbreak due to sterility concerns at the New England Compounding Center.
• A pharmacist was sentenced to prison due to a 2012 fungal meningitis outbreak, which resulted in 76 deaths and hundreds of illnesses.
• Microbial contamination in pharmaceuticals can directly harm patients, leading to health hazards and allergic reactions, degradation in product quality, altered therapeutic activity of the product, and changes to pH.

Types of Contaminations

• Includes Product degradation (spoilage), active ingredients and excipients may be degraded, altering a product's appearance or smell.
• Microbial contamination can cause toxin production, that can include Endotoxin from Gram-negative LPS, Tetanus toxin, and Enteric toxins.
• Other risks include Infections which can also lead to death in severe cases, especially in immunocompromised individuals and neonates.

Route of Administration

• Sterile and non-sterile products affect risk.
• The type of manufacturing site is relevant to contamination risk, including considering registration with regulatory authorities.
• Quality Assurance (QA), Good Manufacturing Practice (GMP), and Quality Control (QC) are crucial.
• Ensuring consistent product quality through controlled production is essential and specified by marketing authorization.
• Sterile product manufacturing requires clean and aseptic areas.

Reported Contaminations

• The table outlines a timeline of reported microbial contaminations in various products across different years.
• In 1907, plague vaccine was contaminated with Clostridium tetani.
• Serum vaccine in 1948 was found to contain Staphylococcus aureus.
• Chloroxylenol, a disinfectant, was contaminated with Pseudomonas aeruginosa in 1955.
• Thyroid tablets contained Salmonella muenchen in 1966.
• That same year, saline solutions were compromised by Serratia marcescens.
• Hand cream was contaminated with Klebsiella pneumoniae in 1967.
• Chlorhexidine-cetrimide was tainted by Burkholderia cepacia in 1970.
• IV fluids in 1972 contained enteric bacteria and Pseudomonas.
• In 1972, Pancreatin powder also had Salmonella agona contamination.
• Contact lens solutions were affected by Serratia and enteric bacteria in 1977.
• Surgical dressings were problematic due to Clostridium spp. in 1981.
• Iodophor solutions showed P. aeruginosa in 1982.
• Aqueous soap harbored P. stutzeri in 1983.
• Finally, in 1986, antiseptic mouthwash had coliform bacteria.

Common Contaminants

• Clostridium tetani can be found at http://www.hpa.org.uk/Topics/InfectiousDisease/s/InfectionsAZ/Tetanus/GeneralInformation/.
• Staphylococcus aureus can be found at http://www.hpa.org.uk/Topics/InfectiousDisease/s/InfectionsAZ/StaphylococcusAureus/ and http://www.hpa.org.uk/Topics/InfectiousDisease/s/InfectionsAZ/PantonValentineLeukocidinPVL.
• Pseudomonas aeruginosa typically grows aerobically and is isolated from various environments.
• P. aeruginosa thrives in mesophilic to psychrophilic temperatures, has varied nutritional needs, forms prolific biofilms, colonizes CF lungs, and has intrinsic/acquired antibiotic resistance.
• can be found at http://www.hpa.org.uk/Topics/InfectiousDiseases/InfectionsAZ/Pseudomonas Aeruginosa/.
• Burkholderia cepacian used to be classified as Pseudomonas and inhabits similar environments;
• B. cepacian has similar nutritional pathways while displaying extreme antibiotic resistance and the ability to colonize CF patients.
• Specific stains of B. cepacian can be pan-antibiotic resistant.

Contamination Frequency in Product Recalls

• Non-sterile product recalls (N=134) showed 48% caused by B. cepacia, P. aeruginosa, or Ralstonia picketti.
• Non-sterile contamination by yeasts and molds accounted for 23% of recalls.
• Additionally, 60% of non-sterile recalls were due to Gram-negatives, while 4% were due to Gram-positives.
• Sterile product recalls (N=193) showed that Gram-negatives caused around 6% and Gram-positives caused 1%.
• The most commonly isolated microbial contaminant is B. cepacia.
• The source for this data is Microbial Diversity in Pharmaceutical Product Recalls and Environments, PDA J Pharm Sci Tech, 2007.

Health Laboratory Investigation of Contamination

• In a sample of 6700 items tested a public health laboratory investigation, around 27% had detectable contamination.
• Contamination ranged from less than 10 organisms to as high as 10⁵ to 10⁶ organisms g¯¹ or mL-¹.
• Investigation has shown that overall contamination rate was similar among different types of pharmaceutical product.
• Frequency of heavy contamination correlates to water availability in the product.
• Gram-positive bacilli and micrococci are generally the majority of contaminants.
• Non-pathogenic contaminants include Yeasts and molds, also common in creams and ointments.

Investigation Observations

• Tables show different level of contamination rate of various types of products.
• Potential pathogens such as Pseudomonas aeruginosa and other pseudomonads are most frequently isolated.

BP Standards on Microbiological Quality

Contamination Sources

• Occurs from contamination of the product itself during manufacturing.
• Also acquired during administration due to substandard techniques.
• Other contamination risks involves use of multi-use vials vs single-use vials.
• Environmental sources may include Airborne particles, contaminated diluents, syringes, and inlet/lines.
• Other environmental risks include that Applicators (sponges, pads) or Equipment (ventilators, resuscitators) can act as sources of contamination.

Human Sources

• Include Personnel, hair, skin, and cosmetics.
• Other human sources can include Fibers from clothing and/or outside contaminants from clothing.
• Training is another relevant route of contamination risk.
• Patients themselves are prolific sources.
• These can include Skin, mucous membranes and the Saliva in the breath.
• Topical antimicrobial creams/ointments that are re-used can contain resistant organisms.