Accession | ARO:3000014 |
Definition | TEM-1 is the most commonly-encountered beta-lactamase in gram-negative bacteria. Up to 90% of ampicillin resistance in E. coli is due to the production of TEM-1. Also responsible for the ampicillin and penicillin resistance that is seen in H. influenzae and N. gonorrhoeae in increasing numbers. Although TEM-type beta-lactamases are most often found in E. coli and K. pneumoniae, they are also found in other species of gram-negative bacteria with increasing frequency. The amino acid substitutions responsible for the ESBL phenotype cluster around the active site of the enzyme and change its configuration, allowing access to oxyimino-beta-lactam substrates. Opening the active site to beta-lactam substrates also typically enhances the susceptibility of the enzyme to b-lactamase inhibitors, such as clavulanic acid. Although the inhibitor-resistant beta-lactamases are not ESBLs, they are often discussed with ESBLs because they are also derivatives of the classical TEM- or SHV-type enzymes. These enzymes were at first given the designation IRT for inhibitor-resistant TEM beta-lactamase; however, all have subsequently been renamed with numerical TEM designations. There are at least 19 distinct inhibitor-resistant TEM beta-lactamases. Inhibitor-resistant TEM beta-lactamases have been found mainly in clinical isolates of E. coli, but also some strains of K. pneumoniae, Klebsiella oxytoca, P. mirabilis, and Citrobacter freundii. Although the inhibitor-resistant TEM variants are resistant to inhibition by clavulanic acid and sulbactam, thereby showing clinical resistance to the beta-lactam-lactamase inhibitor combinations of amoxicillin-clavulanate (Co-amoxiclav), ticarcillin-clavulanate, and ampicillin/sulbactam, they normally remain susceptible to inhibition by tazobactam and subsequently the combination of piperacillin/tazobactam, although resistance has been described. |
Drug Class | penam, monobactam, cephalosporin, penem |
Resistance Mechanism | antibiotic inactivation |
Classification | 12 ontology terms | Show + process or component of antibiotic biology or chemistry + mechanism of antibiotic resistance + determinant of antibiotic resistance + antibiotic molecule + antibiotic inactivation [Resistance Mechanism] + antibiotic inactivation enzyme + hydrolysis of antibiotic conferring resistance + beta-lactam antibiotic + cephem + hydrolysis of beta-lactam antibiotic by serine beta-lactamase + penam [Drug Class] + beta-lactamase |
Parent Term(s) | 6 ontology terms | Show + confers_resistance_to_drug_class monobactam [Drug Class] + confers_resistance_to_drug_class cephalosporin [Drug Class] + confers_resistance_to_drug_class penam [Drug Class] + class A beta-lactamase + confers_resistance_to_antibiotic ampicillin [Antibiotic] + confers_resistance_to_drug_class penem [Drug Class] |
Sub-Term(s) | 238 ontology terms | Show + TEM-1 + TEM-2 + TEM-3 + TEM-4 + TEM-5 + TEM-6 + TEM-7 + TEM-8 + TEM-9 + TEM-10 + TEM-11 + TEM-12 + TEM-13 + TEM-15 + TEM-16 + TEM-17 + TEM-18 + TEM-19 + TEM-20 + TEM-21 + TEM-22 + TEM-24 + TEM-25 + TEM-26 + TEM-27 + TEM-28 + TEM-29 + TEM-30 + TEM-31 + TEM-32 + TEM-33 + TEM-34 + TEM-35 + TEM-36 + TEM-37 + TEM-38 + TEM-39 + TEM-40 + TEM-42 + TEM-43 + TEM-44 + TEM-45 + TEM-46 + TEM-47 + TEM-48 + TEM-49 + TEM-50 + TEM-51 + TEM-52 + TEM-53 + TEM-54 + TEM-55 + TEM-56 + TEM-57 + TEM-58 + TEM-59 + TEM-60 + TEM-61 + TEM-63 + TEM-65 + TEM-66 + TEM-67 + TEM-68 + TEM-70 + TEM-71 + TEM-72 + TEM-73 + TEM-74 + TEM-75 + TEM-76 + TEM-78 + TEM-79 + TEM-80 + TEM-81 + TEM-82 + TEM-83 + TEM-84 + TEM-85 + TEM-86 + TEM-87 + TEM-88 + TEM-89 + TEM-90 + TEM-91 + TEM-92 + TEM-93 + TEM-94 + TEM-95 + TEM-96 + TEM-101 + TEM-102 + TEM-103 + TEM-104 + TEM-105 + TEM-106 + TEM-107 + TEM-108 + TEM-109 + TEM-110 + TEM-111 + TEM-112 + TEM-113 + TEM-114 + TEM-115 + TEM-116 + TEM-117 + TEM-118 + TEM-120 + TEM-121 + TEM-122 + TEM-123 + TEM-124 + TEM-125 + TEM-126 + TEM-127 + TEM-128 + TEM-129 + TEM-130 + TEM-131 + TEM-132 + TEM-133 + TEM-134 + TEM-135 + TEM-136 + TEM-137 + TEM-138 + TEM-139 + TEM-141 + TEM-142 + TEM-143 + TEM-144 + TEM-145 + TEM-146 + TEM-147 + TEM-148 + TEM-149 + TEM-150 + TEM-151 + TEM-152 + TEM-154 + TEM-155 + TEM-156 + TEM-157 + TEM-158 + TEM-159 + TEM-160 + TEM-161 + TEM-162 + TEM-163 + TEM-164 + TEM-165 + TEM-166 + TEM-167 + TEM-168 + TEM-169 + TEM-170 + TEM-171 + TEM-172 + TEM-173 + TEM-174 + TEM-176 + TEM-177 + TEM-178 + TEM-181 + TEM-183 + TEM-186 + TEM-187 + TEM-188 + TEM-189 + TEM-190 + TEM-191 + TEM-192 + TEM-193 + TEM-194 + TEM-195 + TEM-197 + TEM-198 + TEM-199 + TEM-100 + TEM-119 + TEM-140 + TEM-153 + TEM-175 + TEM-179 + TEM-180 + TEM-182 + TEM-185 + TEM-184 + TEM-196 + TEM-200 + TEM-201 + TEM-202 + TEM-203 + TEM-204 + TEM-205 + TEM-206 + TEM-207 + TEM-208 + TEM-209 + TEM-210 + TEM-211 + TEM-212 + TEM-213 + TEM-214 + TEM-215 + TEM-216 + TEM-217 + TEM-218 + TEM-221 + TEM-222 + TEM-219 + TEM-220 + TEM-223 + TEM-224 + TEM-225 + TEM-226 + TEM-227 + TEM-228 + TEM-229 + TEM-230 + TEM-231 + TEM-232 + TEM-233 + TEM-234 + TEM-235 + TEM-236 + TEM-237 + TEM-238 + TEM-240 + TEM-241 + TEM-242 + TEM-243 + TEM-98 + TEM-99 + TEM-246 + TEM-247 + TEM-244 + TEM-245 |
Publications | Bradford PA. 2001. Clin Microbiol Rev 14(4): 933-951. Extended-spectrum beta-lactamases in the 21st century: characterization, epidemiology, and detection of this important resistance threat. (PMID 11585791) Thomson CJ, et al. 1993. Epidemiol. Infect. 110(1):117-25 Molecular epidemiology of the plasmid-encoded TEM-1 beta-lactamase in Scotland. (PMID 8432315) |