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ABSTRACT: To examine the occurrence, diversity and transmission of Campylobacter in a poultry slaughterhouse.
During a 4-week period, a slaughterhouse was sampled alternately during slaughtering and the following mornings post-disinfection. Samples were taken from poultry at six stages in the slaughter process and from 25 environmental sites. For positive broiler flocks slaughtered on one occasion, 92% and 48% of the environmental sites were positive during slaughter and post-disinfection, respectively. For positive laying hen flocks slaughtered on three occasions, 8-56% and 12-20% of the environmental sites were positive during slaughter and post-disinfection, respectively. Genetic fingerprinting by amplified fragment length polymorphism (AFLP) of the 109 isolates obtained resulted in 28 different AFLP clones. Five AFLP clones were present for more than 1 week.
Slaughtering of Campylobacter-positive broilers resulted in extensive contamination of the slaughterhouse, including the air. A high proportion of the laying hen flocks were Campylobacter positive, but these caused less environmental contamination than the broilers. This, together with the freezing of all layer carcasses, results in a lower public health risk from laying hens, when compared with broilers.
When slaughtering Campylobacter-positive broilers, the implementation of preventive measures is important to reduce contamination of negative carcasses and to protect the workers against infection.
Journal of Applied Microbiology 09/2007; 103(2):271-9. · 2.34 Impact Factor
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ABSTRACT: Antimicrobial susceptibility in Campylobacter jejuni collected from the environment outside four broiler houses (n = 63) and from the environment inside these broiler houses (including broiler droppings) (n = 36) from May to September 2004 was studied and compared with isolates from Norwegian broilers analyzed within the frame of the Norwegian monitoring program of antimicrobial resistance in feed, food, and animals (NORM-VET) in 2004 (n = 75). The MICs of oxytetracycline, ampicillin, erythromycin, gentamicin, enrofloxacin, and nalidixic acid were obtained by the broth microdilution method VetMIC. The present study, which to our knowledge is the first Norwegian study on the occurrence of antimicrobial resistance in Campylobacter spp. from the environment of broiler houses, revealed a very low occurrence of antimicrobial resistance in C. jejuni from the broilers and broiler house environments studied. All isolates originating from the four broiler houses studied were susceptible to all the antimicrobial agents tested, except for one isolate from the outdoor environment (courtyard soil), which was resistant to oxytetracycline (MIC, 8 mg/liter). For the isolates from broilers (NORM-VET), low prevalences of resistance to oxytetracycline (1.3%) and ampicillin (4%) were observed. No quinolone resistance was observed. The results for the broiler isolates are in agreement with the earlier findings of a very low prevalence of resistance in Campylobacter from broilers in Norway, which reflects the low usage of antimicrobials in Norwegian broiler production. Furthermore, the present data are in accordance with antimicrobial susceptibility data for C. jejuni from domestically acquired human cases.
Journal of food protection 04/2007; 70(3):736-8. · 1.94 Impact Factor
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ABSTRACT: We examined the occurrence and diversity of Campylobacter jejuni on broiler carcasses during slaughter of an infected flock and in the slaughterhouse environment during slaughter and postdisinfection before a new production run. During the slaughter of a known C. jejuni infected broiler flock, samples were taken from broiler carcasses at 7 different stages during the process. Thirty-seven sites in the slaughterhouse environment were sampled both during process and postdisinfection. The samples were analyzed for C. jejuni, and genetic fingerprinting was performed using amplified fragment length polymorphism. All carcass samples were positive. Of the environmental samples collected during slaughter, 89% were positive; 100% of those from the arrival, stunning, scalding, defeathering, and evisceration facilities and 67% of those from the cooling and sorting facilities. Postdisinfection, 41% of the samples were positive; 71% of those from the arrival and stunning area, 60% of those from the scalding and defeathering area, and 20% of those from the evisceration, cooling, and sorting area. The C. jejuni isolates (n = 60) recovered were grouped into 4 different amplified fragment length polymorphism clones with a similarity index of 95% or greater. All isolates obtained from the flock and 94% of the isolates obtained from the environment during slaughtering belonged to clone A, whereas 1 environmental isolate belonged to each of the clones B and C. Isolates from clones A, B, and D were present postdisinfection. Only clone B was detected on flocks slaughtered during the previous week. The high level and continuous presence of Campylobacter in the environment constitutes a risk for transmission to negative carcasses. In Norway, where above 96% of the broiler flocks are Campylobacter-negative, this aspect is of special importance. The ability of Campylobacter to remain in the slaughterhouse environment through washing and disinfection is associated with constructional conditions of equipment and buildings, complicating cleaning and providing sufficient moisture. To reduce the probability of the workers acquiring campylobacteriosis, precautions should be taken when slaughtering Campylobacter-positive flocks.
Poultry Science 01/2007; 85(12):2278-84. · 1.73 Impact Factor
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ABSTRACT: To investigate the genetic diversity of Campylobacter in broilers and in the environment of broiler farms, to compare the genetic profiles and describe critical factors for transmission to broilers.
Flocks at three of four investigated farms became colonized with Campylobacter. The total proportion of Campylobacter-positive samples at different farms varied from 20% to 42%. The farm with the poorest biosecurity routines had broilers that became infected earliest, the highest proportion of positive samples and the highest genetic diversity among the broiler Campylobacter isolates. Campylobacter isolates within common amplified-fragment length polymorphism (AFLP) clusters (95-100%) were found to be present in outdoor environment and in broilers at adjacent farms before they were found in the broilers. A large presence of Campylobacter in the farm environment was demonstrated after the broilers were infected. A high genetic diversity was found among Campylobacter present in the outdoor environment, where certain Campylobacter clusters were found for periods of up to 6 weeks.
Confirmation by AFLP indicates adjacent poultry farms and outdoor environment as major sources of Campylobacter infection of broilers, this being the novel achievements.
The results provide more exact knowledge on transmission of Campylobacter at farm level, helpful for developing optimal preventive strategies.
Journal of Applied Microbiology 12/2006; 101(5):1130-9. · 2.34 Impact Factor
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ABSTRACT: In this study comprising isolates from 2001 to 2003, resistance was considerably more widespread among Campylobacter jejuni from humans infected abroad than infected within Norway. The discrepancy was particularly notable for fluoroquinolone resistance (67.4% vs. 6.5%). This is probably a reflection of a low resistance prevalence in Norwegian broiler isolates (1.2% fluoroquinolone resistant).
Epidemiology and Infection 03/2006; 134(1):127-30. · 2.84 Impact Factor
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ABSTRACT: Environmental reservoirs of glycopeptide-resistant enterococci (GRE) in Norway have been linked to former growth promoting use of the glycopeptide avoparcin in poultry production. We have examined the prevalence of fecal GRE in poultry and poultry farmers 3 to 8 years after the Norwegian avoparcin ban in 1995 and performed molecular analyses of the GRE population. Fecal samples from poultry farmers and their flocks on 29 previously avoparcin-exposed farms were collected on five occasions during the study period (1998 to 2003). All flocks (100%) were GRE positive in 1998. Throughout the study period, 78.5% of the poultry samples were GRE positive. Glycopeptide-resistant Enterococcus faecium (GREF) was isolated from 27.6% of the farmer samples in 1998 and from 27.8% of the samples collected between 1998 and 2003. The prevalence of fecal GRE in poultry declined significantly during the study period, but prevalence in samples from the farmers did not decline. PCR analysis revealed a specific Tn1546-plasmid junction fragment in 93.9% of E. faecium isolates. A putative postsegregation killing (PSK) system linked to Tn1546 was detected in 97.1% of the isolates examined. Multilocus sequence typing of glycopeptide-susceptible (n = 10) and -resistant (n = 10) E. faecium isolates from humans (n = 10) and poultry (n = 10) on two farms displayed 17 different sequence types. The study confirms the continuing persistence of a widespread common plasmid-mediated vanA-pRE25-PSK element within a heterogeneous GRE population on Norwegian poultry farms 8 years after the avoparcin ban. Moreover, it suggests an important role of PSK systems in the maintenance of antimicrobial resistance determinants in reservoirs without apparent antimicrobial selection.
Applied and Environmental Microbiology 02/2006; 72(1):516-21. · 3.83 Impact Factor
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ABSTRACT: The evolutionary processes responsible for the long-term persistence of glycopeptide-resistant Enterococcus faecium (GREF) in nonselective environments were addressed by genetic analyses of E. faecium populations in animals and humans on two Norwegian poultry farms that were previously exposed to avoparcin. A total of 222 fecal GREF (n = 136) and glycopeptide-susceptible (n = 86) E. faecium (GSEF) isolates were obtained from farmers and poultry on three separate occasions in 1998 and 1999. Pulsed-field gel electrophoresis (PFGE) and plasmid DNA analyses discerned 22 GREF and 32 GSEF PFGE types within shifting polyclonal animal and human E. faecium populations and indicated the presence of transferable plasmid-mediated vanA resistance, respectively. Examples of dominant, persistent GREF PFGE types supported the notion that environmentally well-adapted GREF types may counteract the reversal of resistance. PFGE analyses, sequencing of the purK housekeeping gene, and partial typing of vanA-containing Tn1546 suggested a common animal and human reservoir of glycopeptide resistance. Inverse PCR amplification and sequence analyses targeting the right end of the Tn1546-plasmid junction fragment strongly indicated the presence of a common single Tn1546-plasmid-mediated element in 20 of 22 GREF PFGE types. This observation was further strengthened by vanY-vanZ hybridization analyses of plasmid DNAs as well as the finding of a physical linkage between Tn1546 and a putative postsegregation killing system for seven GREF PFGE types. In conclusion, our observations suggest that the molecular unit of persistence of glycopeptide resistance is a common mobile plasmid-mediated vanA-containing element within a polyclonal GREF population that changes over time. In addition, we propose that "plasmid addiction systems" may contribute to the persistence of GREF in nonselective environments.
Applied and Environmental Microbiology 02/2005; 71(1):159-68. · 3.83 Impact Factor
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ABSTRACT: Rectal swabs from healthy cats and dogs, and from dogs and cats with clinical diarrhoea were collected approximately every third month from May 2000 to June 2001 from six small-animal practices throughout Norway. A questionnaire was filled in for each animal. Of the 301 healthy cats sampled, 54 (18%) were positive for Campylobacter, compared to 5 out of 31 (16%) cats with diarrhoea. Campylobacter jejuni was isolated from 11 (3%), C. upsaliensis from 42 (13%) and C. coli from 2 (0.6%) of the cats sampled. Isolates from four cats (1%) could not be specified. Of the 529 healthy dogs, 124 (23%) were positive for Campylobacter, compared to 18 of 66 (27%) dogs with diarrhoea. C. jejuni was isolated from 20 (3%) and C. upsaliensis from 117 (20%) of the dogs sampled. Isolates from five dogs (0.8%) could not be specified. Eighteen out of the 20 investigated C. upsaliensis samples were resistant to streptomycin. The clinically healthy animals were included in the analysis to identify factors associated with Campylobacter prevalence. The cat model had low classification ability. The dog-data model indicated increased odds of infection with Campylobacter for dogs </=1 year, and in dogs sampled during the spring. No difference was observed between the prevalence of Campylobacter infections in cats and dogs with diarrhoea and healthy animals.
Preventive Veterinary Medicine 11/2002; 55(4):241-53. · 2.05 Impact Factor
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ABSTRACT: Avoparcin was used as a growth promoting feed additive in Norwegian broiler and turkey production from 1986 until it was banned in 1995, when an association between vancomycin-resistant enterococci (VRE) and avoparcin use became apparent. A recent study regarding faecal samples documented a continuing high prevalence of VRE among Norwegian poultry 3 years after avoparcin was banned. In the present study, carcasses of broilers and turkeys from farms where avoparcin had previously been in use and carcasses of layer chickens from farms where avoparcin had never been used were examined for the presence of VRE. One carcass from each of 150 different farms was included. By a direct plating method, VRE were isolated from 30 of 100 samples of broilers and turkeys, but not from any samples of layer chickens. When an enrichment step was included, VRE were isolated from a total of 81 of the 100 samples of broilers and turkeys and from nine of the 50 samples of layer chickens. All VRE isolated were highly resistant to vancomycin (MIC > or = 256 microg/ml) and possessed the vanA gene. These results correspond to the prevalence of VRE recently documented in faecal samples from Norwegian poultry. The present study reveals a high prevalence of VRE in broiler and turkey carcasses. Consequently, consumers are exposed to VRE when handling raw poultry meat, although the public health significance of such exposure is unclear.
International Journal of Food Microbiology 02/2001; 64(1-2):89-94. · 3.33 Impact Factor
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ABSTRACT: Five Norwegian broiler farms previously identified as housing broilers carrying vancomycin-resistant enterococci (VRE) were examined for the presence of VRE 4 years after avoparcin was banned. Environmental samples were obtained from empty, cleaned broiler houses. Faecal samples were collected weekly from the flock housed after the environmental sampling. The hatchery from where the chicks originated was also sampled. VRE were found to be present in the farm environment after depopulation and cleanup of the broiler houses. Within 3 weeks after introduction to the farm, all broiler flocks tested positive for VRE. VRE were not isolated from the hatchery.
FEMS Microbiology Letters 11/2000; 191(2):255-8. · 2.04 Impact Factor
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ABSTRACT: Avoparcin was used as a feed additive in Norwegian broiler and turkey production from 1986 until 1995. It was banned due to the selection of VanA-type vancomycin-resistant enterococci (VRE) in animal husbandry and to reduce the potential for human exposure to VRE. The aim of the present study was to investigate the prevalence of VRE carriage in Norwegian poultry farmers and their poultry three years after avoparcin was banned. Corresponding faecal samples from poultry and humans on farms where avoparcin had previously been used (exposed farms, n = 73) and farms where avoparcin had never been used (unexposed farms, n = 74) were analysed for the presence of VRE. For each farm, one sample from the poultry house and one sample from the farmer were obtained. VRE were isolated from 72 of 73 (99%) and eight of 74 (11%) poultry samples from exposed and unexposed farms, respectively. VRE were isolated from 13 of 73 (18%) and one of 74 (1%) farmer samples from exposed and unexposed farms, respectively. All VRE isolates were highly resistant to vancomycin and possessed the vanA gene, as shown by PCR. The high prevalence of VRE is in accordance with previous Norwegian studies, and shows a remarkable stability of the VanA resistance determinant in an apparently non-selective environment.
Journal of Applied Microbiology 10/2000; 89(3):478-85. · 2.34 Impact Factor
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ABSTRACT: This study documents a strong and statistically significant association between the use of the glycopeptide avoparcin as a growth promoter in Norwegian poultry production and the occurrence of vancomycin-resistant Enterococcus species (VRE). Avoparcin was approved as a feed additive for broilers and turkeys in Norway in 1986 and was banned from June 1, 1995. In a survey conducted in Norway between June, 1995 and March, 1997, VRE were isolated from fecal samples from 106 out of 109 poultry houses previously exposed to avoparcin (97%) and from six out of 33 poultry houses never exposed to avoparcin (18%) (RR = 5.35). Samples from previously exposed poultry houses were collected in three time periods. The proportion of positive samples remained high (96-98%), in all three time periods indicating a persistence of vancomycin resistance among enterococci for more than a year and a half after the withdrawal of avoparcin. VRE were also isolated from six out of 10 poultry farmers living on farms previously exposed to avoparcin, and from none of 16 farmers living on farms never exposed to avoparcin. Moreover, VRE were isolated from 68 out of the 225 broiler carcasses investigated (30%). The resistance to vancomycin was a high-level type (MIC > or = 256 microg/ml) mediated by the vanA gene. For comparison, VRE could only be isolated from two out of 147 fecal samples from Norwegian flocks of swine (1%). Because avoparcin never has been used in Norwegian swine production, this observation strengthens the association between the use of avoparcin in animal husbandry and the occurrence of VRE.
Microbial Drug Resistance 02/1999; 5(2):135-9. · 2.15 Impact Factor
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ABSTRACT: The genetical relatedness between epidemiologically linked fecal VRE strains from poultry farmers (n = 5) and their broilers (n = 7) at five avoparcin-exposed Norwegian farms was examined. Pulsed-field gel electrophoresis (PFGE) of bacterial chromosomal digests and structural analysis of vanA resistance elements was performed. Animal and human Enterococcus faecium strains at one farm were genetically closely related with indistinguishable vanA elements and a single band position difference in PFGE analysis. Examination of the vanA elements in genetically unrelated strains by restriction enzyme digestion of Tn1546 long-PCR amplicons and ORF2-vanR intergenic sequencing revealed a pool of at least two distinct vanA gene cluster groups in the two reservoirs. The results indicate that transmission of VanA glycopeptide resistance in enterococci between human and animal at avoparcin-exposed farms can occur by direct transfer of VRE strains as well as horizontal spread of resistance genes between strains.
Microbial Drug Resistance 02/1998; 4(4):313-8. · 2.15 Impact Factor
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ABSTRACT: To investigate if there is a reservoir of Escherichia coli O157 in Norwegian cattle, faecal samples from 197 cattle herds were screened for E. coli O157 by the use of immunomagnetic separation (IMS) and PCR during the 1995 grazing season. Six E. coli O157:H-isolates were detected in two herds, one isolate in one and five in the other. The isolates carried the stx1, stx2, and eae genes, and a 90 MDa virulence plasmid. They were toxinogenic in a Vero cell assay. From 57 other herds, 137 faecal samples were positive for stx1 and/or stx2 genes detected by PCR run directly on IMS-isolated material. Among these samples, stx2 were the most widely distributed toxin encoding genes. No difference was found among milking cows and heifers in the rate of stx1 and/or stx2 in positive samples.
Epidemiology and Infection 02/1998; 120(1):21-8. · 2.84 Impact Factor
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ABSTRACT: In a retrospective study, 1538 strains of beta-haemolysin-producing Staphylococcus species isolated from dermatitis in dogs at three veterinary clinical microbiology laboratories in Norway during 1986-87 and 1993-94 were investigated for their antimicrobial susceptibility. None of the strains was resistant to cloxacillin, cephalexin or the quinolones enrofloxacin and ciprofloxacin. More than 96% of the strains were susceptible to trimethoprim-sulphonamide, bacitracin and fucidic acid. Between 67% and 89% of the strains were susceptible to erythromycin, lincosamides, tetracycline, neomycin and chloramphenicol. Only 37.9% of the strains were susceptible to penicillin. The frequency of penicillin resistance increased significantly between the first and second periods, from 46.0% to 58.6%. The frequency of resistance to lincomycin, clindamycin and erythromycin also increased significantly between the first and second periods, from 3.0%, 2.1% and 3.3% to 25.5%, 19.5% and 24.8%, respectively. A moderate increase in resistance to tetracycline was also noted, from 20.4% in the first to 27.6% in the second period. On the other hand, the frequency of resistance to trimethoprim-sulphonamide decreased significantly from 4.1% in the first to 0.9% in the second period. Many different resistance patterns were observed in each period. However, the proportion of multiresistant strains increased from 2.1% in the first to 10.2% in the second period. There was a decrease in resistance to the combination of trimethoprim-sulphonamide and penicillin from the first to the second period. Resistance to the combination of lincosamides and penicillin increased. For the combinations penicillin-tetracycline-lincosamides, penicillin-lincosamides-erythromycin, and penicillin-tetracycline-lincosamides-erythromycin, there was a striking increase in resistance between the first and the second periods.
Veterinary Research Communications 02/1996; 20(3):205-14. · 0.82 Impact Factor
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ABSTRACT: Ten multiple antimicrobial-resistant isolates of Vibrio cholerae O1 isolated from patients in Uganda were characterized, and the transferability of resistance to bacteria of diverse origins was investigated. The isolates were toxigenic and belonged to biotype E1 Tor, serotype Ogawa, and ribotype 8, and possessed a 130-MDa plasmid of incompatibility group 6-C. This plasmid, designated pRVC1, was shown to confer resistance to trimethoprim (mediated by a dhfrI gene), sulfonamides (a suII gene), tetracycline [a tet(C) gene], chloramphenicol (a catI gene), ampicillin (a beta-lactamase gene other than blaTEM or blaSHV), and streptomycin. pRVC1 proved to be transmissible at frequencies between 1 x 10(-1) and 5 x 10(-6) transconjugants per recipient to a variety of bacterial pathogens, including those of humans, animals, and fish. Most efficient transfer was observed from V. cholerae to strains of Shigella flexneri, Escherichia coli, Vibrio parahaemolyticus, and three Aeromonas species. The present in vitro study suggests that pRVC1 may spread from V. cholerae to other bacteria pathogenic to man, animals, and fish in natural environments.
Microbial Drug Resistance 02/1995; 1(3):203-10. · 2.15 Impact Factor
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ABSTRACT: Plasmids harboring multiple antimicrobial-resistance determinants (R plasmids) were transferred in simulated natural microenvironments from various bacterial pathogens of human, animal, or fish origin to susceptible strains isolated from a different ecological niche. R plasmids in a strain of the human pathogen Vibrio cholerae O1 E1 Tor and a bovine Escherichia coli strain were conjugated to a susceptible strain of the fish pathogenic bacterium Aeromonas salmonicida subsp. salmonicida in marine water. Conjugations of R plasmids between a resistant bovine pathogenic E. coli strain and a susceptible E. coli strain of human origin were performed on a hand towel contaminated with milk from a cow with mastitis. A similar conjugation event between a resistant porcine pathogenic E. coli strain of human origin was studied in minced meat on a cutting board. Conjugation of R plasmids between a resistant strain of the fish pathogenic bacterium A. salmonicida subsp. salmonicida and a susceptible E. coli strain of human origin was performed in raw salmon on a cutting board. R plasmids in a strain of A. salmonicida subsp. salmonicida and a human pathogenic E. coli strain were conjugated to a susceptible porcine E. coli strain in porcine feces. Transfer of the different R plasmids was confirmed by plasmid profile analyses and determination of the resistance pattern of the transconjugants. The different R plasmids were transferred equally well under simulated natural conditions and under controlled laboratory conditions, with median conjugation frequencies ranging from 3 x 10(-6) to 8 x 10(-3). The present study demonstrates that conjugation and transfer of R plasmids is a phenomenon that belongs to the environment and can occur between bacterial strains of human, animal, and fish origins that are unrelated either evolutionarily or ecologically even in the absence of antibiotics. Consequently, the contamination of the environment with bacterial pathogens resistant to antimicrobial agents is a real threat not only as a source of disease but also as a source from which R plasmids can easily spread to other pathogens of diverse origins.
Applied and Environmental Microbiology 12/1994; 60(11):4015-21. · 3.83 Impact Factor
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ABSTRACT: The antibacterial resistance pattern and minimum inhibitory concentrations (MIC) of 25 Shigella flexneri, 5 S. boydii, 8 S. sonnei, and 3 strains of S. dysenteriae type 2 isolated from Kenyan prostitutes with bacillary dysentery and AIDS were determined, and the applicability of the E-test for MIC determination evaluated. All strains were resistant to > or = 3 of 9 different antibacterial agents tested. All strains were resistant to tetracycline and erythromycin, 95% to trimethoprim/sulfonamide, 93% to streptomycin, 54% to ampicillin, 39% to chloramphenicol, 2% to nalidixic acid and none to gentamicin and ciprofloxacin. Six different resistance patterns were observed. The most common pattern was resistance to tetracycline, erythromycin, trimethoprim/sulfa and streptomycin (39%). The E-test was shown to be well-suited for susceptibility testing of multiresistant Shigella spp.; the reproducibility was excellent and the correlation with the microtiter dilution method and the disk diffusion method were 98% in both instances. The MIC measured with E-test and the microdilution method were within +/- 1 dilution step for 94.4% of the combinations tested.
Scandinavian Journal of Infectious Diseases 01/1992; 24(6):733-9. · 1.72 Impact Factor
