On 2015 Mar 20, Daniel Haft commented:

The authors demonstrate that HcpA, a cysteine-rich repeat protein from Helicobacter pylori, slowly hydrolyzes 6-aminopenicillinic acid and 7-aminocephalosporanic acid derivatives, and therefore has some beta-lactamase activity. However, low-level beta-lactamase activity is inherent in penicillin-binding proteins involved in cell wall biosynthesis (the natural targets of beta-lactam antibiotics) and in a number of proteins whose biological role likewise is something other than antibiotic resistance. Works citing this paper tend not to dwell on the observed weak beta-lactamase activity or on the authors' suggestion that HcpA might contribute to insensitivity to amoxicillin in resistant strains. An apparent role for HcpA as a secreted pro-inflammatory virulence factor is described in PMID:16040986. I suggest that this protein be named "cysteine-rich repeat protein HcpA" rather than "beta-lactamase HcpA" for purposes of genome annotation. Beta-lactamases conferring antimicrobial resistance but outside the Ambler classes A, B, C, and D are still not known as of early 2015.

On 2015 Mar 20, Daniel Haft commented:

The authors demonstrate that HcpA, a cysteine-rich repeat protein from Helicobacter pylori, slowly hydrolyzes 6-aminopenicillinic acid and 7-aminocephalosporanic acid derivatives, and therefore has some beta-lactamase activity. However, low-level beta-lactamase activity is inherent in penicillin-binding proteins involved in cell wall biosynthesis (the natural targets of beta-lactam antibiotics) and in a number of proteins whose biological role likewise is something other than antibiotic resistance. Works citing this paper tend not to dwell on the observed weak beta-lactamase activity or on the authors' suggestion that HcpA might contribute to insensitivity to amoxicillin in resistant strains. An apparent role for HcpA as a secreted pro-inflammatory virulence factor is described in PMID:16040986. I suggest that this protein be named "cysteine-rich repeat protein HcpA" rather than "beta-lactamase HcpA" for purposes of genome annotation. Beta-lactamases conferring antimicrobial resistance but outside the Ambler classes A, B, C, and D are still not known as of early 2015.