Comparative Activity of Several Antimicrobial Agents against Nosocomial Gram‐Negative Rods Isolated across Canada

Abstract

SR SCRIVER, CANA DIAN ANTI MI CRO BIAL RESIS TANCE STUDY GROUP, DE LOW.Com para tive ac tiv ity of sev eral an ti mi crobial agents against no so comial Gram-negative rods iso lated across Can ada. Can J In fect Dis 1995;6(2):76-82. In 1992, a sur veil lance study was per formed in Can ada to de ter mine the sus cep ti bil ity of no so comial Gram-negative rods to sev eral wide spec trum an ti mi cro bi als. Con secu tive iso lates from 10 in sti tu tions, as well as ad di tional strains of se lected spe cies of En tero bac te riaceae that are known to pos sess the Bush group 1 beta-lactamase, were tested for sus cep ti bil ity to 12 an ti mi cro bi als. Third-generation cepha lo sporin re sis tance was found to be as high as 29% in En terobac ter cloa cae that pos sesses the Bush group 1 beta-lactamase and less than 4% in those iso lates not pos sess ing this en zyme. Ce fepime equalled or ex ceeded the ac tiv ity of the third-generation cepha lo sporins against the spe cies of Entero bac te riaceae that dem on strated re sis tance to the third-generation cepha lo sporins. Key Words: An ti mi cro bial re sis tance, Gram-negative rods Activité comparative de plusieurs antibiotiques contre les souches nosocomiales gram-négatives isolées au CanadaRÉS UMÉ : En 1992, une étude épidémi olo gique a été ef fec tuée au Can ada afin de dé ter mi ner le de gré de sen si bil ité des souches noso comia les Gram-négatives à di vers anti bio tiques à large spec tre. Des iso lats consé cu tifs prove nant de dix établis se ments, de même que d'autres souches d'e spèces sé lec tionnées d'En tero bac te riaceae dont on sait qu'elles sont do tées de bêta-lactamases Bush de groupe 1 ont été sou mis à des épreu ves de sen si bil ité à 12 an ti mi crobiens. Une résis tance de l'or dre de 29 % aux cépha lo spor ines de troisième gé né ra tion a été ob servée dans une souche d'En tero bac ter cloa cae do tée de bêta-lactamases Bush du groupe 1, et infé rieure à 4 % dans les iso lats dépour vus de cet en zyme. La céfépime a mani festé une ac tiv ité égale ou supé rieure aux cépha lo spor ines de troisième gé né ra tion con tre les espèces d'En tero bac te riaceae qui mani fes taient une résis tance aux cépha lo spor ines de troisième gé né ration. 76CAN J INFECT DIS VOL 6 NO 2 MARCH/APRIL 1995

Study of the Comparative Activity of Piperacillin/Tazobactam with Currently Available Antibiotics against 8206 Aerobic Isolates

“…We identified one strain from a hospital in Toronto that demonstrated the typical susceptibility profile of ESBLs extended-spectrum beta-lactamases. This finding is consistent with other recently published surveys of Canadian strains (20). This is in sharp contrast to the experience in many other countries where both endemic and epidemic strains are frequently encountered (21)(22)(23)(24)(25).…”

Enterobacter spp.: pathogens poised to flourish at the turn of the century.

“…For the aminoglycosides, the percentage of strains resistant to gentamicin ranges from 0 to 51%, the percentage resistant to tobramycin ranges from 0 to 43%, and the percentage resistant to amikacin ranges from 0 to 34% (25, 34, 71, 84, 85, 99, 127, 132, 141, 160, 176, 198, 206, 212, 215, 223-225, 232, 244). For ciprofloxacin, resistance varies from 0 to 36% of strains tested, and for trimethoprim-sufamethoxazole, resistance varies from 0 to 60% of strains (34,71,85,99,127,132,141,160,198,212,213,215,216,223,224,232,244). These wide ranges suggest that numerous factors impact the occurrence of antimicrobial resistance among strains of Enterobacter.…”

Low Prevalence of Gastrointestinal Colonization with Antimicrobial‐Resistant Bacteria in High Risk Units in a Canadian Tertiary Care Centre

“…This study is not directly comparable with ours because it enrolled all patients, not just those admitted to high risk units, and clinical isolates from all sites, not exclusively gastrointestinal carriage. The Gram-negative isolates in our high risk units, however, showed a prevalence of antimicrobial resistance comparable with or more sensitive than those of the cross-Canada study (19). One Klebsiella species isolate was resistant to cefotaxime; the exact mechanisms of this organism's resistance to cefotaxime were not established.…”

“…In addition, many recent studies have considered all nosocomial isolates and not specifically the bowel flora (18). In Canada (19)(20)(21), however, the emergence of nosocomial antimicrobial resistance, to date, has not reached the proportions reported in the United States (5,8,22) or overseas (13).…”

“…Prevalence of VRE is highly variable among institutions, but in at least one New York facility, between 28.6% and 64% of patients receiving intravenous vancomycin had VRE detected on rectal swabs (26). A recent study (19) reported cross-Canada resistance profiles of nosocomial Gram-negative bacteria. This study is not directly comparable with ours because it enrolled all patients, not just those admitted to high risk units, and clinical isolates from all sites, not exclusively gastrointestinal carriage.…”