Gram-negative bacilli

Penicillin prototype active against common streptococci, gram-positive bacilli, gram-negative cocci, spirochetes (drug of choice in syphilis), and enterococci (if used with an aminoglycoside) penicillinase-susceptible. Tox penicillin allergy. 

Benzylpenicillin or penicillin G has a narrow antimicrobial spectrum. It is active with respect to Gram-positive bacteria (staphylococcus, streptococcus, and pneumococci), causative agent of diphtheria, and anthrax bacillus. Gram-negative bacteria are resistant to it. Benzylpenicillin is broken down by stomach acid and destroyed by staphylococcus penicillinase. 

These compounds showed a remarkable activity toward Gram-positive (e.g.. Bacillus cereus, Staphylococcus aureus, Sarcina luted) and Gram-negative bacteria (e.g.. Pseudomonas sp.) the activity was somewhat lower in the styryl derivatives (82MI2). 

Polymyxin B Bacillus polymyxa Gram-negative bacteria Cell membrane... 

V. cholerae is a gram-negative bacillus. Vibrios pass through the stomach to colonize the upper small intestine. Vibrios have filamentous protein extensions that attach to receptors on the intestinal mucosa, and their motility assists with penetration of the mucus layer.2 The cholera enterotoxin consists of two subunits, one of which (subunit A) is transported into the cells and causes an increase in cyclic AMP, which leads to a deluge of fluid into the small intestine.20 This large volume of fluid results in the watery diarrhea that is characteristic of cholera. The stools are an electrolyte-rich isotonic fluid, the loss of which results in blood volume depletion followed by low blood pressure and shock.2 Of note, the diarrheal fluid is highly infectious. 

Antibacterial activity of macrolides depends on the acidity of the medium. High activity is observed in neutral and basic media in comparison with acid. In particular, erythromycin is inactivated in the acidic medium of the stomach. Macrolides have a relatively broad spectrum of use, and they are active with respect to Gram-positive and Gram-negative microorganisms, achiomycetes, mycoplasma, spirochaeta, chlamydia. Bacteria Rickettsia, certain mycobacteria. Colon bacillus, blue-pus bacillus, shigella, salmonella, and so on. 

Kanamycin A is similar to streptomycin and neomycines and has a broad spectrum of antimicrobial action. It is active with respect to most Gram-positive as well as Gram-negative microorganisms (staphylococci, gastric bacilli, rabbit fever, Fridlender s bacillus, proteus, shigella, salmonella). 

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