Did you know?
Oxidase-positive bacteria, like Pseudomonas aeruginosa, thrive in oxygen-rich environments, making infections significantly harder to treat.
Oxidase Positive
Researched by:
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Karen Pendergrass
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Karen Pendergrass
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease—four years before the first published case study.
Oxidase positivity in an organism refers to the ability of the organism to produce the enzyme cytochrome c oxidase, which is involved in the electron transport chain during aerobic respiration.
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Karen Pendergrass
Researched by:
-
Karen Pendergrass
ID
Karen Pendergrass
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Karen Pendergrass
Overview Overview
Oxidase positive or oxidase positivity is an important characteristic in bacterial identification because it provides information about the organism’s respiratory enzyme system, specifically the presence of cytochrome c oxidase. This enzyme is part of the electron transport chain used in aerobic respiration, and its presence or absence is a key biochemical trait used to differentiate bacterial species.
Pathogenic Implications of Oxidase Positivity
Oxidase-positive bacteria, particularly those causing human infections, possess highly efficient respiratory systems that allow them to thrive in oxygen-rich environments, such as the lungs or bloodstream. This adaptability makes them more virulent and harder to treat in these conditions. Their robust metabolism not only enhances their survival in aerobic environments but also contributes to antibiotic resistance. For instance, Pseudomonas aeruginosa, an oxidase-positive bacterium, is notorious for its multidrug resistance, making it especially challenging for clinicians to manage infections, as it can persist and proliferate in oxygen-rich tissues even under treatment.
Oxidase Positive Pathogens
This table includes oxidase-positive species, detailing their pathogenic status and the types of infections or conditions they are associated with.
| Species | Pathogen Status |
| Pseudomonas aeruginosa | Opportunistic pathogen that causes infections in immunocompromised individuals, such as in cystic fibrosis, burns, and hospital-acquired infections. |
| Neisseria gonorrhoeae | Causes gonorrhea, a sexually transmitted infection. |
| Neisseria meningitidis | Causes bacterial meningitis and septicemia. |
| Vibrio cholerae | Causes cholera, a severe diarrheal disease. |
| Campylobacter jejuni | Causes gastroenteritis, leading to diarrhea and abdominal pain). |
| Helicobacter pylori | Causes peptic ulcers and is linked to stomach cancer. |
| Alcaligenes faecalis | Opportunistic pathogen that can cause infections in immunocompromised individuals, especially respiratory infections. |
| Moraxella catarrhalis | Causes respiratory infections such as bronchitis and pneumonia, particularly in children and the elderly. |
| Aeromonas hydrophila | Opportunistic pathogen, associated with gastroenteritis, wound infections, and sepsis. |
| Legionella pneumophila | Causes Legionnaires’ disease, a severe form of pneumonia. |
| Brucella spp. | Causes brucellosis, a zoonotic disease. |
| Pasteurella multocida | Causes infections, often following animal bites or scratches. |
| Vibrio vulnificus | Can cause wound infections, septicemia, and is associated with consumption of contaminated seafood. |
| Haemophilus influenzae | Causes respiratory infections, including pneumonia and meningitis. |
| Shewanella putrefaciens | Opportunistic pathogen that can cause wound infections and bacteremia, especially in immunocompromised individuals. |
| Bordetella pertussis | Known pathogen that causes whooping cough. |
| Vibrio parahaemolyticus | Causes gastroenteritis, commonly associated with raw or undercooked seafood. |
Conclusion
Oxidase positivity matters because it is a key biochemical trait used in identifying, classifying, and understanding bacterial species. It provides insights into a bacterium’s respiratory system, ecological role, and potential pathogenicity. In both clinical and environmental contexts, the oxidase test is a simple, rapid, and informative diagnostic tool that aids in differentiating bacterial species and guiding treatment decisions.