Reference | Study | Key findings relevant to antimicrobial resistance | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
Typea | subjects | country | time period | bacterial target | relevant study outcomes | sample size | controls | comments | ||
GRADE level: Controlled trial | ||||||||||
Not applicable because of ethical concerns | ||||||||||
GRADE level: observational study | ||||||||||
[87] | CC | human patients | U.S. | 1999–2001 | Salmonella Newport; MDRAmpC resistant | risk factors for infection | 34 cases; 37 infected controls and 94 community controls | Salmonella patients with susceptible Newport infection; healthy community controls | followed up by investigation of cattle isolates and risk factors for shedding on dairy farms; regional in scope (New England) | Association of infection with Salmonella Newport MDRAmpC with dairy farm exposure; bacterial isolates from humans and cattle were indistinguishable or closely related (based on antibiotic resistance profile and PFGE pattern) |
[88] | CC | human patients | U.S. | 2002–2003 | Salmonella Newport; MDRAmpC resistant | risk factors for infection | 215 case patients; 54 with MDRAmpC resistant strain and 146 pansusceptible; 1154 community controls | healthy community controls; volunteers without diarrhea in the previous 28 days | FoodNet study; national in scope (8 of 9 FoodNet sites) | Association of infection with Salmonella Newport MDRAmpC with consumption of uncooked ground beef or home prepared runny scrambled eggs or omelets during the 5 days before onset of illness |
[89] | CC | human patients in Wisconsin | U.S. | 2003–2005 | Salmonella Newport MDR AmpC | associations between antimicrobial resistance and reported exposures | 268 isolates from Wisconsin and 402 from the remaining U.S. | Cases in Wisconsin vs. rest of the U.S. | Controls were collected 2003–2004 | Infections with multidrug-resistant Salmonella Newport strains were associated with exposures to cattle, farms and unpasteurized milk |
[90] | CC | human patients in California | U.S. | 1985 | Salmonella Newport (chloramphenicol resistant) | risk factors for infection | 45 patients and 89 matched controls | healthy volunteers | Epidemic Salmonella strain was isolated from hamburger products eaten by cases, as well as the abattoirs where the animals were slaughtered, dairies that sent the animals to slaughter, and ill dairy cows. | Association of infection with resistant Salmonella Newport isolates with eating ground beef during the week before onset and penicillin and tetracycline use during the month before onset of symptoms; chloramphenicol resistant Salmonella from dairy farms were associated with chloramphenicol use on those dairies |
[91] | CC | human patients from national database | Netherlands | 2003–2005 | MRSA (non-typable) | risk factors for infection | 35 cases, 76 controls | MRSA infections with other strains | Analysis aimed to exclude secondary cases | Living in rural areas and contact with pigs and cattle were associated with case patients |
[92] | CS | veal calf farmers | Netherlands | 2007–2008 | MRSA ST 398 | risk factors for carriage | 102 farms, 390 questionnaires, 2151 nasal swabs from calves | farmers negative for MRSA ST 398 | nasal swabs taken from farmers and farm calves; farms randomly selected | Human MRSA ST 398 carriage was associated with intensity of animal contact and number of positive animals on farm; calves were more likely to be carriers when treated with antibiotics, and good farm hygiene had a protective effect. |
[93] | CS | swine farmers | Belgium | 2007 | MRSA ST 398 | risk factors for carriage | 49 swine farms, 127 persons on the farms participated and 1500 pigs were sampled | farmers negative for MRSA ST 398 | nasal swabs and wound samples; farms randomly collected | MRSA ST 398 carriage by farmers was associated with prevalence among pigs on the farm, having regular contact with pigs, dogs, and horses, and use of protective equipment. |
GRADE level: other | ||||||||||
[22] | phylogenetic study | bacterial isolates | various | 1997–2011 | MRSA CC398 | evolution and transmission dynamics including transmission between species | n/a | none | Phylogenetic and population genetic analysis | human and animal populations of CC398 are separate, but with multiple transfers back and forth; same data suggesting onward transmission of animal-associated strains in community settings (e.g., hospitals); different tetracycline resistance genes showed different evolutionary patterns |
[94] | outbreak | human patients with rare strain | Denmark | 1998 | Salmonella Typhimurium DT104 | source of multidrug resistant infection outbreak | 27 cases | none | rare strain isolated from patients and pork samples; pork samples were traced back to herd; resistant infections in humans were more difficult to treat | A swine herd was the likely source of a human outbreak with MDR Salmonella Typhimurium DT104 |
[95] | outbreak | human patients infected with rare strains | U.S. | 1983 | Salmonella Newport | source of multidrug resistant infection outbreak | 18 cases | none | rare isolate strain found in human patients and cattle | hamburger from beef cattle fed sub therapeutic chlortetracycline for growth promotion likely outbreak source |
[96] | human case report | human patient infected with rare strain | U.S. | 1998 | Salmonella Typhimurium | source of multidrug resistant infection | 1 case | none | Infection traced back to farm; | The farm was identified as the source of a multidrug resistant Salmonella isolate from a human case patient |
[97] | human case report | MRSA cluster around pig farmer | Netherlands | 2004 | MRSA | source of multidrug resistant infection | pig farmer, family and co-workers, pigs | none | animals on farm sampled | Infection with MRSA traced back to farm, onward transmission in farm family |
[98] | correlation study | Isolates from swine and swine workers | U.S. | Unspecified | MRSA | risk factors for MRSA colonization | 20 workers and 299 swine | none | animals and humans sampled | Colonization with MRSA ST 398 was very common in swine herds, similar isolates in humans and animals |
[99] | correlation study | isolates from farm personnel and milk samples | Hungary | 2002–2004 | MRSA | risk factors for MRSA colonization | 1 farm, 12 workers sampled, 595 milk samples | none | MRSA strains were subtyped | MRSA isolates from workers in close contact with cows were indistinguishable from cow isolates |