Pseudomonas

Classificação

Características Gerais

• Bacilo Gram-negativo
• Encapsulado
• Móvel: 1–3 flagelos móveis
• Aeróbio obrigatório
• Oxidase-positivo
• Catalase-positivo
• Fermentação sem lactose
• Produz um pigmento azul-esverdeado: devido à produção de piocianina e fluoresceína
• Produz um odor frutado característico de uva
• Espécies clinicamente relevantes: Pseudomonas aeruginosa Pseudomonas aeruginosa A species of gram-negative, aerobic, rod-shaped bacteria commonly isolated from clinical specimens (wound, burn, and urinary tract infections). It is also found widely distributed in soil and water. P. Aeruginosa is a major agent of nosocomial infection. Pseudomonas ( P. aeruginosa P. aeruginosa A species of gram-negative, aerobic, rod-shaped bacteria commonly isolated from clinical specimens (wound, burn, and urinary tract infections). It is also found widely distributed in soil and water. P. Aeruginosa is a major agent of nosocomial infection. Pseudomonas)

Patogénese

Reservatório e transmissão

Reservatório:

• Onipresente no ambiente
• Reservatórios húmidos:
  • Pias
  • Equipamento respiratório e de diálise

Transmissão:

• Transmissão de pessoa para pessoa através de reservatórios infetados

Fatores de risco

• Neutropenia Neutropenia Neutrophils are an important component of the immune system and play a significant role in the eradication of infections. Low numbers of circulating neutrophils, referred to as neutropenia, predispose the body to recurrent infections or sepsis, though patients can also be asymptomatic. Neutropenia
• Queimaduras
• Asplenia Asplenia Asplenia is the absence of splenic tissue or function and can stem from several factors ranging from congenital to iatrogenic. There is a distinction between anatomic asplenia, which is due to the surgical removal of the spleen, and functional asplenia, which is due to a condition that leads to splenic atrophy, infarct, congestion, or infiltrative disease. Asplenia
• Fibrose quística
• Intubação endotraqueal
• Algaliação crónica

Patogénese de P. aeruginosa P. aeruginosa A species of gram-negative, aerobic, rod-shaped bacteria commonly isolated from clinical specimens (wound, burn, and urinary tract infections). It is also found widely distributed in soil and water. P. Aeruginosa is a major agent of nosocomial infection. Pseudomonas

Doenças causadas por P. aeruginosa

Antimicrobianos

Tratamento

• P. aeruginosa P. aeruginosa A species of gram-negative, aerobic, rod-shaped bacteria commonly isolated from clinical specimens (wound, burn, and urinary tract infections). It is also found widely distributed in soil and water. P. Aeruginosa is a major agent of nosocomial infection. Pseudomonas tem resistência variável a antibióticos:
  • Multirresistente: resistente a pelo menos 1 agente em > 3 categorias de antibióticos
  • Extensivamente resistente a fármacos: resistente a pelo menos 1 agente em todas as categorias de antibióticos, exceto 2
  • Resistente a medicamentos: resistente a todas as categorias de antibióticos
• A escolha do antibiótico é adaptada aos padrões de resistência local (antibioterapia combinada):
  • 1ª linha:
    • Combinação de inibidores de penicilina/ beta-lactamase Beta-Lactamase Penicillins (piperacilina/ tazobactam Tazobactam A penicillanic acid and sulfone derivative and potent beta-lactamase inhibitor that enhances the activity of other anti-bacterial agents against beta-lactamase producing bacteria. Cephalosporins)
    • Cefalosporinas (ceftazidima)
    • Monobactam ( aztreonam Aztreonam The carbapenems and aztreonam are both members of the bactericidal beta-lactam family of antibiotics (similar to penicillins). They work by preventing bacteria from producing their cell wall, ultimately leading to bacterial cell death. Carbapenems and Aztreonam)
    • Fluoroquinolonas (ciprofloxacina) (apenas oral)
    • Carbapenemes ( meropenem Meropenem A thienamycin derivative antibacterial agent that is more stable to renal dehydropeptidase I than imipenem, but does not need to be given with an enzyme inhibitor such as cilastatin. It is used in the treatment of bacterial infections, including infections in immunocompromised patients. Carbapenems and Aztreonam)
  • As estirpres resistentes a vários fármacos são tratadas com antibióticos recém-desenvolvidos:
    • Combinações de inibidores de beta-lactama-beta-lactamase (ceftolozano/ tazobactam Tazobactam A penicillanic acid and sulfone derivative and potent beta-lactamase inhibitor that enhances the activity of other anti-bacterial agents against beta-lactamase producing bacteria. Cephalosporins)
    • Cefalosporinas ( cefiderocol Cefiderocol Multidrug-resistant Organisms and Nosocomial Infections)
    • Combinação de carbapenem-beta-lactamase (imipenem-cilastatina-relibactam)
    • Polimixinas
  • Antibióticos adjuvantes: aminoglicosídeos (tobramicina, gentamicina, amicacina)

Prevenção

• Higiene no hospital:
  • Uso de técnicas estéreis apropriadas
  • Limpeza cuidadosa de pias e chuveiros comuns
• Monitorização periódica, substituição e limpeza de:
  • Equipamento de suporte respiratório
  • Linhas intravenosas (IV) (especialmente de longo-termo)
  • Catéteres

Mnemónica

Para ajudar a memorizar os aspetos clinicamente mais MAIS Androgen Insensitivity Syndrome relevantes sobre Pseudomonas Pseudomonas Pseudomonas is a non-lactose-fermenting, gram-negative bacillus that produces pyocyanin, which gives it a characteristic blue-green color. Pseudomonas is found ubiquitously in the environment, as well as in moist reservoirs, such as hospital sinks and respiratory equipment. Pseudomonas, utilize a mnemónica “ PSEUDOMONAS Pseudomonas Pseudomonas is a non-lactose-fermenting, gram-negative bacillus that produces pyocyanin, which gives it a characteristic blue-green color. Pseudomonas is found ubiquitously in the environment, as well as in moist reservoirs, such as hospital sinks and respiratory equipment. Pseudomonas”

• Pneumonia, pyocyanina – Pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia e piocianina
• Sepsis – Sépsis
• Ecthyma gangrenosum – Éctima gangrenoso
• UTIs – ITUs (Infeções do trato urinário)
• Diabetes, Drug use – Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus, utilizadores de Drogas
• Osteomyelitis – Oesteomielite
• Mucoid, polysaccharide capsule Capsule An envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides. Bacteroides – cápsula polissacarídica mucoide
• Otitis externa – Otite externa (“ouvido de nadador”)
• Nosocomial infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease – Infeções nosocomiais (cateteres, tubos endotraqueais)
• Exotoxin A – Exotoxina A
• Skin infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease – Infeções cutâneas (foliculite de “banheira de hidromassagem” e queimaduras)