confers_resistance_to_drug_class cephalosporin confers_resistance_to_drug_class penicillin beta-lactam SHV beta-lactamase antibiotic_resistance ARO:3000015 SHV-1 shares 68 percent of its amino acids with TEM-1 and has a similar overall structure. The SHV-1 beta-lactamase is most commonly found in K. pneumoniae and is responsible for up to 20% of the plasmid-mediated ampicillin resistance in this species. ESBLs in this family also have amino acid changes around the active site, most commonly at positions 238 or 238 and 240. More than 60 SHV varieties are known. SHV-LEN beta-lactamase