]> 2026-07-31T09:40:56+00:00 WBR294 0 en Linezolid Linezolid and aminoglycosides block the formation of initiation complex, thereby inhibiting protein synthesis. Tetracycline Tetracycline blocks the entry and binding of aminoacyl transfer RNA, thereby inhibiting protein synthesis. Quinupristin/dalfopristin Quinupristin/dalfopristin and other streptogramins block peptidyl transferase which forms peptide bonds between adjacent amino acids using tRNAs during the translation process. Clindamycin Clindamycin and macrolides block translocation by binding to the 50S rRNA of the large bacterial ribosome subunit. Chloramphenicol Chloramphenicol blocks peptidyl transferase which forms peptide bonds between adjacent amino acids using tRNAs during the translation process. ''E. coli'' O157:H7 (EHEC) is negative for invasiveness (Sereny test), adheres through the ''E. coli'' common pilus (ECP), and does not produce either heat-stable or heat-labile toxins. In addition, ''E. coli'' O157:H7 is usually sorbitol-negative, whereas other ''E. coli'' ferment sorbitol. Among the virulence factors, Shiga-like toxin (SLT-1) is an iron-regulated toxin that catalytically inactivates 60S ribosomal subunits of eukaryotic cells. It cleaves N-glycoside bond of adenine in 28S rRNA of the 60S ribosome unit to prevent EF-1-dependent aminoacyl tRNA binding, thereby inhibiting protein synthesis. This mechanism of action is similar to tetracyclines, which also inhibit protein synthesis by blocking the entry and binding of aminoacyl transfer RNA.<br/> '''Educational Objective:''' Among the virulence factors of ''E. coli'' O157:H7, Shiga-like toxin (SLTs) is an iron-regulated toxin that catalytically cleaves N-glycoside bond of adenine in 28S rRNA of the 60S ribosome unit to prevent aminoacyl tRNA binding, thereby inhibiting protein synthesis. This mechanism of action is similar to tetracyclines, which also inhibit protein synthesis by blocking the entry and binding of aminoacyl transfer RNA.<br/> '''References:''' First Aid 2015 page 138. Microbiology A 28-year-old man presents to the clinic with abdominal cramps, general malaise, fever, and diarrhea 6 hours after consuming ground beef. Few leukocytes are found in his fecal specimen. Growth of colorless colonies on sorbitol-MacConkey agar is noted. The pathogen produces toxins which contain enzymatic subunits that interfere with protein synthesis. Which of the following antibiotics has a similar mechanism regarding to the toxin's action on translation? B Gastrointestinal 2020-10-28T03:02:05Z 2459150.6264468 WBR294