Penicillin sensitization

Staphylococcus aureus cells can acquire large DNA fragments containing the mecA gene which encodes a complete new penicillin binding protein 2A (PBP 2A), as part of a transposon. PBP2A can substitute the natural set of penicillin-sensitive PBPs thereby mediating a complete cross resistance to all (3-lactam antibiotics. 

The answer is c. (Hardman, pp 1135-1141.) Erythromycin, a macro-lide antibiotic, was initially designed to be used in penicillin-sensitive... 

The isolate is penicillin sensitive (MIC less than or equal to 0.1 mcg/mL). / There are no cardiovascular risk factors such as heart failure, aortic insufficiency, or conduction abnormalities. 

A monobactam that is only active against gram-negative bacteria, including some strains of P. aeruginosa. Generally useful for nosocomial infections when aminoglycosides are to be avoided and in penicillin-sensitive patients. 

J. M. Frere, B. Joris, Penicillin-Sensitive Enzymes in Peptidoglycan Biosynthesis , Crit. Rev. Microbiol. 1985,1, 299-396. 

The hydrolysed surface of Ihe Si3N4 insulator functions as a pH-sensitive membrane [90, 105, 116, 179]. A penicillin-sensitive ISFET is based on this membrane that is covered by an immobilized layer of penicillinase, converting penicillin into the penicillanic acid anion with liberation of hydrogen ions [24]. Another version of pH-sensitive ISFETs has membrane gates made of TajOs [3] or of a suitable glass [39]. The latter ISFET with a gate made of alumino- or borosilicate glass is sensitive to sodium ions. Other ISFETs are sensitive to halide ions [22, 153, 178], [105, 115, 130] and Ca [90, 105]. 

The widespread occurrence of penicillin sensitivity, and the survival of penicillin residues in meat following cooking, led Katz to point out that "since up to 10% of the population is potentially sensitive to penicillin and its breakdown products, the risk is too great to be ignored," and to warn against injections unless these are carefully controlled. The use of withdrawal procedures should protect consumers against possible sensitivity reactions from penicillin residues. 

Oral Penicillins generally are indicated in the treatment of mild to moderately severe infections caused by penicillin-sensitive microorganisms. 

Hypersensitivity reactions Serious and occasionally fatal immediate-hypersensitivity reactions have occurred. The incidence of anaphylactic shock is between 0.015% and 0.04%. Anaphylactic shock resulting in death has occurred in approximately 0.002% of the patients treated. These reactions are likely to be immediate and severe in penicillin-sensitive individuals with a history of atopic conditions. 

Hematologic/Lymphatic Anemia hemolytic anemia thrombocytopenia thrombocytopenic purpura eosinophilia leukopenia granulocytopenia neutropenia bone marrow depression agranulocytosis reduction of hemoglobin or hematocrit prolongation of bleeding and prothrombin time decrease in WBC and lymphocyte counts increase in lymphocytes, monocytes, basophils, and platelets. Hypersensitivity Adverse reactions (estimated incidence, 1% to 10%) are more likely to occur in individuals with previously demonstrated hypersensitivity. In penicillin-sensitive individuals with a history of allergy, asthma, or hay fever, the reactions may be immediate and severe. 

Cross-allergenicity with penicillin Administer cautiously to penicillin-sensitive patients. There is evidence of partial cross-allergenicity cephalosporins cannot be assumed to be an absolutely safe alternative to penicillin in the penicillin-allergic patient. The estimated incidence of cross-sensitivity is 5% to 16% however, it is possibly as low as 3% to 7%. 

Streptococcal In penicillin-sensitive alpha and nonhemolytic streptococci, use streptomycin for 2 weeks with penicillin 1 g twice daily for 1 week, 0.5 g twice daily for the second week. If patient is older than 60 years of age, give 0.5 g twice daily for the entire 2-week period. 

Staphylococcal strains which are able to produce beta-lactamase remain sensitive to the beta-lacta-mase-resistant penicillins such as cloxacillin and flucloxacillin. However the beta-lactamase-resistant penicillins appeared, at least in vitro, to be less active against those bacterial strains that are still penicillin-sensitive. 

When culture results of CSE and/or blood are available therapy should always be streamlined. If the meningococcus, pneumococcus, group B streptococcus or Listeria are penicillin sensitive, this small spectrum agent (benzylpenicillin 6x3 million units/day i.v.) would be the therapy of choice. 

Empiric treatment for subacute endocarditis likely to be caused by penicillin-sensitive streptococci consists of high dose penicillin G (6 x 3 million units i.v. daily) plus gentamicin (1x3 mg/kg). In acute endocarditis a staphylococcal etiology is more likely and, therefore, gentamicin is combined with (flu)cloxacillin (6 x 2 g i.v. daily). 

Mectianism of Action A diagnostic agent that invokes immunoglobulin E which produces type I accelerated urticarial reactions to penicillins. Therapeutic Effect A positive reaction will suggest penicillin sensitivity. 

Staphylococcus aures (penicillin-sensitive) Staphyloccocus aureus (penicillin-resistant) Streptococcus pyogenes Streptococcus pneumoniae Enterococcus faecalis ... 

Warnings If patient is penicillin-sensitive, caution should be used because there have been reports of cross-hypersensitivity among beta-lactam antibiotics Pseudomembranous colitis has been reported... 

Streptococcus pneumoniae Arthritis otitis pneumonia sinusitis If penicillin sensitive ampicillin or penicillin G or V If penicillin resistant vancomycin rifampin A cephalosporin erythromycin azithromycin clarithromycin imipenem meropenem a fluoroquinolone trimethoprim-sulfamethoxazole... 

Cephalosporin antibiotics are especially useful for treating infections in patients who are allergic to penicillins. Hypersensitivity to cephalosporins is much less common, and only about 5-10% of penicillin-sensitive patients will also be allergic to cephalosporins. 

F Ishino, K Mitsui, S Tamaki, M Matsuhashi. Dual enzyme activities of cell wall peptidoglycan synthesis peptidoglycan transglycosylase and penicillin-sensitive transpeptidase in purified preparations of Escherichia coli penicillin-binding protein la. Biochem Biophys Res Commun 97 287-293, 1980. 

M Adam, C Damblon, B Plaitin, L Christiaens, JM Frere. Chromogenic depsipep-tide substrates for 3-lactamases and penicillin-sensitive DD-peptidases. Biochem J 270 525-529, 1990. 

PM Blumberg, JL Strominger. Interaction of penicillin with the bacterial cell penicillin-binding proteins and penicillin-sensitive enzymes. Bacteriol Rev 38 291-335, 1974. 

It is known that p-lactamase catalyzes the rapid hydrolysis of the p-lactam ring of penicillins and cepharosporines. The hydrolytic activity of these enzymes eliminates the bacteriocidal action of many p-lactam antibiotics and makes the organism resistant to these molecules. For this reason, the p-lactamase inhibitors have long been regarded as promising targets from a medicinal viewpoint. A comparison between the kinetic characteristics of p-lactamase and penicillin-sensitive enzymes (carboxy-peptidase and transpeptidase) is of interest in this respect. p-Lactamases very efficiently hydrolyze p-lactam in contrast to penicillin-sensitive enzymes [high /e4 in Eq. (9)]. 

It was noted that she had gram-negative rods on her blood smear her blood culture grew penicillin-sensitive Streptococcus pneumoniae, in 6 hours. At autopsy, she was noted to have Streptococcus pneumoniae endocarditis of the right ventricle, focal ischemia of the left ventricle, bilateral pleural effusions, hepatic congestion with thrombosis, renal congestion, bilateral adrenal hemorrhage, and necrosis. Death was due to septic shock from Streptococcus pneumoniae. 

Due to its powerful specific activity against commonly isolated community-acquired respiratory tract pathogens [33,149-158], including penicillin-sensitive and -resistant Streptococcus pneumoniae, methicillin-sensitive Staphylococcus aureus, Haemophilus spp., Moraxella catarrhalis and atypical pathogens such as Mycoplasma pneumoniae, Chlamydia pneumoniae and Legionella pneumophila and Klebsiella pneumoniae and anaerobic bacteria [159-162], moxifloxacin was developed as a respiratory tract anti-infective [163-168]. 

J-Lactams Passive diffusion, OmpF and OmpC porins Not applicable (interact with penicillin-sensitive enzymes on outer face of IM)... 

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