Proteus resistance

Bacteria which are almost always sensitive to the sulphonamides include Strep, pneumoniae, /3-haemolytic streptococci, Escherichia coli and Proteus mirabilis those almost always resistant include Enterococcus faecalis, Ps. aeruginosa, indole-positive Proteus and Klebsiella whereas bacteria showing a marked variation in response include Staph, aureus, gonococci, El. influenzae and hospital strains of E. coli and Pr. mirabilis. 

Resistance to quinolones by efflux has been described in Staph, aureus and Proteus mirabilis. This gene has been designated nor A in Staph, aureus and is homologous to membrane transport proteins coupled to the electromotive force. These proteins have the ability to remove small amounts of quinolone from cells normally and nor A may have arisen as a result of mutations under selective pressure from quinolone use, resulting in a transport protein with increased affinity for these agents. 

Members of the genus Proteus are unusually resistant to high concentrations of ehlorhexidine and other cationic biocides and are more resistant to EDTA than most other types of Gram-negative bacteria. A less acidic type of LPS may be responsible... 

Complicated exacerbation FEV, less than 50% predicted Comorbid cardiac disease Greater than or equal to 3 exacerbations per year Antibiotic therapy in the previous 3 months Above organisms plus drug-resistant pneumococci, P-lactamase-producing H. influenzae and M. catarrhalis, Escherichia coli, Proteus spp., Enterobacter spp., Klebsiella pneumoniae Oral P-Lactam/P-Iactamase inhibitor (amoxicil 1 i n-clavulanate) Fluoroquinolone with enhanced pneumococcal activity (levofloxacin, gemifloxacin, moxifloxacin) Intravenous P-Iactam/P-Iactamase inhibitor (ampicillin-sulbactam) Second- or third-generation cephalosporin (cefuroxime, ceftriaxone) Fluoroquinolone with enhanced pneumococcal activity (levofloxacin, moxifloxacin)... 

The answer is c. (Hardman, p 1086.) Ticarcillin resembles carbenicillin and has a high degree of potency against Pseudomonas and Proteus organisms but is broken down by penicillinase produced by various bacteria, including most staphylococci. Oxacillin, cloxacillin, nafcillin, and dicloxacillin are all resistant to penicillinase and are effective against staphylococci. 

Gentamicin has a broad spectrum of biological action, and is highly active with respect to strains of staphylococci that are resistant to penicilhns and other antibiotics, many Gramnegative microorganisms blue-pus bacillus, rabbit fever, enterobacter, salmonella, shigella, and proteus. 

The first-generation and oldest quinolones exhibit limited gram-negative activity. Nalidixic acid and cinoxacin do not achieve systemic antibacterial levels and are thus restricted to therapy of bladder infections caused by urinary pathogens, such as E. coli and Klebsiella and Proteus spp. Although they are bactericidal agents, their use is restricted by resistance. 

It is formed by acylases that cleave off the side chain of the penicillins, and can also be obtained by the selective chemical cleavage of the amide, leaving the lactam intact. After this, 6-APA can be easily acylated by any carboxylic acid, and this has yielded literally thousands of semisynthetic penicillins in the past 30 years, many showing improved stability and activity. Some of them are lactamase resistant (methicillin (9.41), oxacillin (9.42) and its halogenated derivatives), whereas others are broad-spectrum antibiotics, like the orally active ampicillin (9.43), which also inhibits Gramnegative bacteria but is sensitive to lactamase. Carbenicillin (9.44) is particularly active against Pseudomonas and Proteus infections, which are unaffected by natural penicillins. Piperacillin (9.45), a broad-spectrum compound, is spectacularly active against Pseudomonas. 

It is bacteriostatic and but bactericidal against many gram positive and negative organisms in higher concentration and acidic urine. Pseudomonas aeruginosa and various strains of Proteus are resistant. It... 

It is obtained from Micromonospora pupurea. It has broader spectrum of action and is effective against Pseudomonas aeruginosa, E. coli, Klebsiella, Enterobacter and Proteus. Streptococci and enterococci are relatively resistant to it owing to failure of the drug to penetrate into the cell. Following parenteral administration, it defuses mainly into extracellular fluids. 

It is semisynthetic derivative of kanamycin. It is active against gentamicin resistant organisms e.g. Pseudomonas aeruginosa, Klebsiella, E. coli and Proteus. It is resistant to bacterial aminoglycoside inactivating enzymes. 

Tetracyclines modify the normal flora, with suppression of susceptible coliform organisms and overgrowth of pseudomonas, proteus, staphylococci, resistant conforms, Clostridia, and Candida. This can result in intestinal functional disturbances, anal pruritus, vaginal or oral candidiasis, or enterocolitis with shock and death. 

The polymyxins are a group of basic peptides active against gram-negative bacteria and include polymyxin and polymyxin E (colistin). Polymyxins act like cationic detergents. They attach to and disrupt bacterial cell membranes. They also bind and inactivate endotoxin. Gram-positive organisms, proteus, and neisseria are resistant. 

Nitrofurantoin is bacteriostatic and bactericidal for many gram-positive and gram-negative bacteria but P aeruginosa and many strains of proteus are resistant. There is no cross-resistance between nitrofurantoin and other antimicrobial agents and resistance emerges slowly. As Escherichia coli resistant to trimethoprim-sulfamethoxazole and fluoroquinolones has become more common, nitrofurantoin has become an important alternative oral agent for treatment of uncomplicated urinary tract infection. 

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