Prevalence, numbers, and subtypes of Campylobacter jejuni and Campylobacter coli in uncooked retail meat samples

A national quantitative survey of Campylobacter jejuni and Campylobacter coli in 1,011 uncooked retail meat samples (beef, unweaned veal, chicken, lamb and mutton, and pork) was undertaken from August 2003 to June 2004 to establish baseline proportionality data. The presence, number, and type of Campylobacter present in each sample was assessed. Prevalences of C. jejuni and C. coli were 89.1% in chicken, 9.1% in pork, 6.9% in lamb and mutton, 3.5% in beef, and 10% in unweaned veal. C. jejuni was identified in the majority of positive samples (246 of 259). In chicken samples positive for C. jejuni, 40.2% had counts of <0.3 most probable number (MPN)/g, 50.5% had 0.3 to 10.0 MPN/g, 8.8% had 10.1 to 50.0 MPN/g, and 0.5% had 110 MPN/g. In other meats (49 samples), Campylobacter counts were < or = 0.3 MPN/g, except for one unweaned veal sample at > 10.9 MPN/g. Penner serotyping and SmaI macrorestriction genotyping using pulsed-field gel electrophoresis with 247 isolates revealed 17 Penner serotypes and 56 electrophoresis profiles. Seven Penner serotypes (HS1 complex, 2, 4 complex, 6, 11, 27, and 42) were represented by 10 or more isolates from chicken. When data from both typing methods were combined, 62 sero-genotypes were generated. In a comparison of these sero-genotypes with historical data for isolates from human cases, 71% of the beef isolates, 50% of the lamb and mutton isolates, 50% of the pork isolates, 41% of the chicken isolates, and 25% of the unweaned veal isolates were common to both sources. These results provide baseline proportionality profiles of Campylobacter in these five meats and will facilitate exposure assessment in combination with other information such as consumption data and subsequent quantitative risk assessment.     

2010—2012年新疆乌鲁木齐地区零售生肉中沙门菌污染情况调查

通过对2010—2012年新疆乌鲁木齐地区零售生肉中沙门菌的检测分析,了解沙门菌污染情况,掌握乌鲁木齐地区零售肉品中沙门菌污染动态变化。方法 按照沙门菌检验国家标准GB/T 4789.1—2010对乌鲁木齐地区的零售肉(鸡肉、羊肉、牛肉、猪肉)检测分离沙门菌并进行血清型分型。结果 2010—2012年共检测1406份零售生肉样品,生鸡肉的感染率达到9.14%,生猪肉为9.06%,生羊肉为8.05%,生牛肉为6.44%,检测共分离得到123株沙门菌,经血清型鉴定可以分为4个血清群,7种血清型,分别为肠炎沙门菌(n=17)、萨奥沙门菌(n=9)、塔西沙门菌(n=8)、乌干达沙门菌(n=6)、康科德沙门菌(n=3)、汤姆逊沙门菌(n=3)和德尔卑沙门菌(n=2),未定型沙门菌75株。结论 新疆乌鲁木齐地区零售肉类中存在沙门菌污染,沙门菌菌株为不同的表型,地区内生肉品中沙门菌污染不容忽视,需要加强对零售肉市场的卫生检疫,防控沙门菌病。     

Surveillance and antimicrobial resistance of Salmonella strains isolated from slaughtered pigs in Spain

The prevalence of and the antibiotic resistance shown by Salmonella isolated from pigs in Andalusia (southern Spain) is reported. Salmonella enterica was recovered from 40 (33%) of 121 sampled herds, and a total of 65 isolates were serotyped. The most common Salmonella serotypes were Typhimurium and Rissen (30.7% each); others included Derby (9.2%), Brandenburg (9.2%), Newport (7.7%), Bredeney (4.6%), Anatum (3.0%), Hadar (1.5%), and Goldcoast (1.5%). One strain (1.5%) belonging to the monophasic variant of the Typhimurium serotype (Salmonella 4,5,12:i: -) was also detected. Definitive phage type (DT) 104b was the most common Typhimurium phage type isolated. These Salmonella strains were resistant to various antimicrobial agents, including tetracycline (84.6%), streptomycin (69.2%), neomycin (63.0%), sulfonamides (61.5%), ampicillin (53.8%), and amoxicillin (53.8%). All isolates were fully susceptible to ceftriaxone, ciprofloxacin, and colistin. Thirty-nine strains (64%) resistant to four or more antimicrobial agents were defined as multidrug resistant. Multidrug resistance profiles were observed in Salmonella serotypes Typhimurium, Rissen, Brandenburg, Bredeney, a monophasic variant, Gold-coast, Hadar, and Anatum, with serotypes Typhimurium and Brandenburg showing the most complicated resistance patterns (resistant to > or = 11 drugs).     

乌鲁木齐市零售牛羊肉中沙门氏菌的调查

目的通过对乌鲁木齐零售牛羊中的沙门氏菌检测分离并分型,了解乌鲁木齐市牛羊肉的污染状况。方法按照沙门氏菌检验国家标GB/T 4789.1-2010对乌鲁木齐零售牛羊肉检测分离并进行血清型分型。结果2013~2014年共检测535份零售牛羊肉样品,共分离得到30株沙门氏菌,总体感染率为5.6%,羊肉的感染率为6.5%,牛肉感染率为4.3%,经血清分型鉴定可以分为5个血清群,12个血清型主要有哈达尔沙门氏菌、伦敦沙门氏菌、肠炎沙门氏菌、姆班达卡沙门氏菌和哈瓦那沙门氏菌等。结论新疆乌鲁木齐地区零售牛羊肉中存在沙门氏菌污染,沙门氏菌菌株为不同的表型,需要加强对零售牛羊肉市场的卫生检疫,防控沙门氏菌疾病。     

Salmonella spp. shedding by alberta beef cattle and the detection of Salmonella spp. in ground beef

Breeder cows, cattle recently arrived at feedlots, and cattle about to be shipped for slaughter were tested for Salmonella spp. No Salmonella spp. were detected in fecal samples from breeding cows. Nineteen of 1,000 (1.9%) fecal samples from recently arrived feedlot cattle were positive for Salmonella spp. compared to only 2 of 1,000 (0.2%) fecal samples taken within 2 weeks of slaughter. The positive fecal samples were collected in 5 of 50 (10%) "recent arrival" pens tested and in 1 of 50 (2%) pens tested within 2 weeks of slaughter. The serotypes isolated were Salmonella Agona, Salmonella Enteritidis, Salmonella Typhimurium DT104, and Salmonella 4,5,12:i:-. Ground beef samples purchased from retail outlets throughout Alberta were processed for Salmonella spp. Thirteen of 1,002 (1.3%) samples were positive for Salmonella spp. The serotypes isolated from ground beef were Salmonella Anatum, Salmonella Heidelberg, Salmonella Montevideo, Salmonella Typhimurium, Salmonella Typhimurium var. Copenhagen, and Salmonella Rough-O:i:1,2. The antibiotic resistance and pulsed-field electrophoresis gel macrorestriction patterns of all isolates were compared.     

Contamination of Salmonella in retail meats and shrimps in the Mekong Delta, Vietnam

From March 2000 to September 2001, 608 samples of retail meat (136 pork, 70 beef, 202 chicken, and 200 ducks) and 110 samples of retail shrimp from six provinces of the Mekong Delta in Vietnam were collected individually and examined for the prevalence of Salmonella. Of the 718 samples examined, 243 (33.8%) were Salmonella positive. Salmonella was isolated from 69.9% of the pork samples, 48.6% of the beef samples, 21.0% of the chicken meat samples, 22.3% of the duck meat samples, and 24.5% of the shrimp samples. From 261 Salmonella isolates, 24 different serovars were identified. The predominant serovars of the isolates were Salmonella Derby, Salmonella Weltevreden, and Salmonella London in pork; Salmonella Weltevreden, Salmonella London, and Salmonella Dessau in beef; Salmonella Emek, Salmonella Typhimurium, and Salmonella Dessau in chicken meat; Salmonella Lexington, Salmonella Derby, and Salmonella Dessau in duck meat; and Salmonella Weltevreden, Salmonella Tennessee, and Salmonella Dessau in shrimps. Salmonella Bovismorbificans, Salmonella Derby, Salmonella Dessau, and Salmonella Weltevreden were the most common serovars in all the samples examined. These results indicate a high rate of contamination by Salmonella in retail meats and shrimps in the Mekong Delta, Vietnam.     

零售生鸡肉中沙门菌污染对居民健康影响的暴露评估

目的评估零售生鸡肉中沙门菌污染的健康风险及其潜在的干预措施。方法利用零售生鸡肉中沙门菌定量监测数据以及零售和家庭生鸡肉储存加工专项调查结果,采用Monte Carlo概率评估方法,估计我国居民通过厨房内交叉污染发生鸡源性沙门菌食物中毒的风险,并评价潜在的干预措施效果。结果本研究构建了从零售到餐桌的生鸡肉-沙门菌交叉污染模型,模型估计生鸡肉经过零售储存、抵达居民家里和经过家庭储存后其沙门菌浓度(lg MPN/g)从零售前的-0.017,分别增长到2.163、2.241和3.028,估计我国居民每餐发生鸡源性沙门菌食物中毒的风险为0.171(95%置信区间:0.000~0.767),其中零售阶段生鸡肉的储存方式是影响发病风险的最重要因素(回归系数=0.72),情景分析提示,如果零售阶段采用冷冻或者冷藏储存,我国居民每餐发病风险可以降为0.031(95%置信区间:0.000~0.522)。结论我国居民鸡源性沙门菌食物中毒的风险较高,应当加强零售环节生鸡肉的冷链管理。     

Quantitative effect of refrigerated storage time on the enumeration of Campylobacter, Listeria, and Salmonella on artificially inoculated raw chicken meat

Active monitoring of pathogens on retail foods has been recommended and implemented in a number of developed countries. Because only a portion of retail food is contaminated with pathogens, a cost-effective and informative surveillance program at the retail level often involves a two-stage approach of initial presence-absence analysis and subsequent pathogen enumeration in any positive samples. Most-probable-number (MPN) methods are more resource intensive and therefore used only for samples considered positive by presence-absence methods. Interpretation of the results assumes that the initial bacterial count remains relatively stable between the initiation of the presence-absence analysis and the enumeration analysis. The objective of this study was to quantify the influence of 4 degrees C storage for 5 and 8 days on pathogen counts on raw chicken. The three pathogens examined were Salmonella Typhimurium, Campylobacter jejuni, and Listeria monocytogenes. No significant differences were found between treatments for Salmonella and Campylobacter. However, significant differences were observed for Listeria; counts at day 0 were lower than counts after 5 or 8 days of refrigerated storage (the maximum mean difference was less than 0.6 log units). These findings suggest that a two-stage approach could overestimate the number of Listeria cells on chicken at the time of purchase. By using an MPN analysis on the presumptive positive samples after 5 days of refrigerated storage, this difference will be reduced. These findings support the decision to reduce surveillance costs by performing a two-stage analysis for Salmonella and Campylobacter on retail chicken. This study provides direction for future sampling or surveillance programs that include enumeration of Listeria on retail food.     

Changes in the composition of the fatty acids and aldehydes of meat lipids after heating

The effects of heating at 132°C on the fatty acids and fatty aldehydes of neutral lipids and phospholipids of lean beef, veal, lamb, pork and chicken were studied. Heating caused hydrolysis of the plasmalogens in the phospholipids, and varying amounts of the liberated fatty aldehydes were recovered in the neutral lipid fractions. Beef phosphatidyl choline lost more polyunsaturated fatty acids than that of the other meats. Beef and veal phosphatidyl ethanolamine lost more polyunsaturated fatty acid than that of lamb, pork or chicken, but the effect was obscured by the influx of fatty acids from elsewhere into this fraction after heating.     

Antibiotic resistance of Aeromonas hydrophila isolated from marketed fish and prawn of South India

From February to November 1999, 198 samples of chicken meat for sale in retail outlets and supermarkets in nine provinces of Castilla and León (Spain) were analysed for the prevalence of Salmonella and Campylobacter. Salmonella was isolated from 71 (35.83%) of the samples analysed. The predominant serovars were S. enteritidis (47.88%), S. hadar (25.35%) and serotype 4,12:b:-(II) (19.71%). Other serovars such as S. mbandaka, S. derby, S. virchow and S. paratyphi B were isolated in much lower levels. Thermophilic campylobacters were isolated in 49.50% of the samples studied.     

Antibiotic resistance profiles of Salmonella serovars isolated from retail pork and chicken meat in North Vietnam

The spread of antibiotic resistance via meat poses a serious public health concerns. During 2007-2009, a total of 586 retail meat samples (318 pork and 268 chicken meats) were collected from three provinces (Bac Ninh, Ha Noi and Ha Tay) of North Vietnam to determine the prevalence of Salmonella. Isolates were characterized by serotyping and antibiotic susceptibility testing. Approximately 39.6% (n=126) of pork and 42.9% (n=115) of chicken samples were Salmonella-positive, and 14 Salmonella serovars were identified. Anatum (15.8%) was the most common serovar, followed by Infantis (13.3%), Emek (10.4%), Derby and Rissen (9.5%), Typhimurium (9.1%), Reading (7.5%) and London (6.2%). The isolation frequency of serovars Enteritidis, Albany, Hadar, Weltevreden, Newport and Blockey ranged from 1.2%-5.8%. Resistance to at least one antibiotic agent was detected in 78.4% of isolates (n=189) and the most frequent resistance were to tetracycline (58.5%), sulphonamides (58.1%), streptomycin (47.3%), ampicillin (39.8%), chloramphenicol (37.3%), trimethoprim (34.0%) and nalidixic acid (27.8%). No Salmonella isolates were resistant to ceftazidime. Chicken isolates had higher resistance to antibiotic agents than pork isolates (P<0.05). It showed that 159 Salmonella isolates belong to the 14 serovars were multidrug resistant (MDR) and 50 MDR patterns were found. This study indicated that Salmonella serovars isolated from retail meat samples were resistant to multiple antibiotics and this resistance was widespread among different serovars. The widespread resistance may have arisen from misuse or overuse of antibiotics during animal husbandry in North Vietnam.     

Acute infection of swine by various Salmonella serovars

The objective of this study was to evaluate the ability of various serovars of Salmonella enterica subsp. enterica to infect alimentary and nonalimentary tissues of swine within 3 h of inoculation. Fourteen wild-type S. enterica serovars (4,12:imonophasic, 6,7 nonmotile, Agona, Brandenburg, Bredeney, Derby, Heidelberg, Infantis, Muenchen, Thompson, Typhimurium, Typhimurium variant Copenhagen, untypeable, and Worthington), two known virulent S. enterica serovars (Choleraesuis strain SC-38 and Typhimurium strain chi4232), and two avirulent S. enterica Choleraesuis vaccine strains (Argus and SC-54) were inoculated intranasally (approximately 5 x 10(9) cells) into swine (four animals per Salmonella isolate). Three hours after inoculation, animals were euthanized, and both alimentary tissues (tonsil, colon contents, and cecum contents) and nonalimentary tissues (mandibular lymph node, thymus, lung, liver, spleen, ileocecal lymph node, and blood) were collected for Salmonella isolation. All Salmonella serovars evaluated except Salmonella Choleraesuis SC-54 acutely infected both alimentary and nonalimentary tissues. These results indicate that Salmonella isolates commonly found in swine are capable of acutely infecting both alimentary and nonalimentary tissues in a time frame consistent with that in which animals are transported and held in lairage prior to slaughter.     

杨凌及周边地区零售分割鸡肉中沙门菌污染状况及耐药和分型特征研究

目的研究陕西杨凌及周边地区零售分割鸡肉中沙门菌的污染状况及其药敏性、血清型和基于脉冲场凝胶电泳(PFGE)的基因型,为预警食源性沙门菌疾病暴发提供数据基础。方法采用GB 4789.4—2010《食品安全国家标准食品微生物学检验沙门氏菌检验》对陕西杨凌及周边地区采集的188份零售分割鸡肉中沙门菌进行分离和鉴定,并进行血清学分型。采用PFGE方法确定沙门菌DNA酶切电泳图谱,使用BioNumerics软件聚类分析电泳结果,确定沙门菌基因型。结果 188份零售分割鸡肉中共有34份(18.1%)样品检出沙门菌,农贸市场样品沙门菌检出率(24.6%,29/118)高于超市(7.1%,5/70)。鸡腿、鸡爪、鸡脖和鸡肝样品中沙门菌检出率高于鸡肠和鸡胗。34株沙门菌中共检出10种血清型,其中科瓦利斯沙门菌最为流行,高于德尔卑沙门菌和鼠伤寒沙门菌等,差异有统计学意义(P0.05)。分离株均对磺胺异噁唑、氯霉素、头孢噻呋和环丙沙星耐药,对甲氧苄啶/磺胺甲噁唑、萘啶酮酸、四环素、链霉素、氨苄西林和阿莫西林/克拉维酸的耐药率均在50%以上。34株沙门菌PFGE分型后可被分为11个簇,同一血清型菌株基本聚于同一大簇,同一时间、从相同市场采集的不同样品,其分离株PFGE型相似度均较高,表明分割鸡肉在加工或销售过程可能存在交叉污染。农贸市场分离菌株基因型多样性比较丰富。结论杨凌及周边地区零售分割鸡肉存在沙门菌污染,沙门菌血清型和基因型多样化,耐药菌株比例较高。     

Validation of a tertiary model for predicting variation of Salmonella typhimurium DT104 (ATCC 700408) growth from a low initial density on ground chicken breast meat with a competitive microflora

Growth of a multiple antibiotic-resistant strain (ATCC 700408) of Salmonella Typhimurium definitive phage type 104 (DT104) from a low initial density (10(0.6) most probable number [MPN] or CFU/g) on ground chicken breast meat with a competitive microflora was investigated and modeled as a function of time and temperature (10 to 40 degrees C). MPN and viable counts (CFU) on a selective medium with four antibiotics enumerated the pathogen. Data from five replicate challenge studies per temperature were combined and fit to a primary model to determine maximum specific growth rate (micro), maximum population density (Nmax), and the 95% prediction interval (PI). Nonlinear regression was used to obtain secondary models as a function of temperature for micro, Nmax, and PI, which ranged from 0.04 to 0.4 h(-1), 1.6 to 9.4 log MPN or CFU/g, and 1.4 to 2.4 log MPN or CFU/g, respectively. Secondary models were combined with the primary model to create a tertiary model for predicting variation (95% PI) of pathogen growth among batches of ground chicken breast meat with a competitive microflora. The criterion for acceptable model performance was that 90% of observed MPN or CFU data had to be in the 95% PI predicted by the tertiary model. For data (n=344) used in model development, 93% of observed MPN and CFU data were in the 95% PI predicted by the tertiary model, whereas for data (n=236) not used in model development but collected using the same methods, 94% of observed MPN and CFU data were in the 95% PI predicted by the tertiary model. Thus, the tertiary model was successfully verified against dependent data and validated against independent data for predicting variation of Salmonella Typhimurium DT104 growth among batches of ground chicken breast meat with a competitive microflora and from a low initial density.     

Prevalence, antibiotic resistance, and molecular characterization of Salmonella serovars in retail meat products

The prevalence of Salmonella was determined in chicken meat (n = 26), beef (n = 49), and pork (n = 56) collected from wholesale markets, retail stores, and traditional markets in Seoul, South Korea, in 2009. Antibiotic resistance was assessed, and the molecular subtypes of Salmonella isolates were ascertained using an automated repetitive sequence-based PCR (rep-PCR) system (DiversiLab). A total of 18 Salmonella strains were isolated from 17 of 131 samples: 16 strains from each of 16 samples and 2 strains from the same pork sample. The prevalence of Salmonella from the retail meats was 2.0% in beef, 8.9% in pork, and 42.3% in chicken meat. Among 10 different serotypes, Salmonella enterica Panama was recovered from a beef sample, and Salmonella London and Salmonella Montevideo were the predominant serotypes from pork and chicken meat, respectively. The highest antibiotic resistance observed was to erythromycin (100%) followed by streptomycin (22.2%) and tetracycline and chloramphenicol (16.7%). Of the 18 isolates, 5 (27.8%) were resistant to two or more antibiotics, and 1 isolate from chicken meat was resistant to eight antibiotics, including cephalosporins. Differentiation between all of the Salmonella isolates except between Salmonella Montevideo and Salmonella London was successfully performed with the automated rep-PCR system, indicating that it can be added to the toolbox for source tracking of foodborne pathogens associated with outbreaks.     

Total Heme and Non-heme Iron in Raw and Cooked Meats

ABSTRACT: This study provides data on the total heme and non-heme iron contents in poultry (chicken, turkey), beef, veal, lamb, horse, ostrich, rabbit, and pork meat cuts. The effect of cooking on heme iron content was also studied. Total iron and heme iron contents markedly differed between muscles in poultry. Heme iron in red meats ranged from 72 to 87%. Heme iron in rabbit and pork was 56 and 62% of total iron. Heating decreased heme iron, the severity of the losses depended on cooking methods: in poultry, losses ranged from 22 to 43%; less severe impact was detected in pan-cooked meat, where the losses ranged from 1 to 24%.     

Effect of coffee filtrate, methylglyoxal, glyoxal, and caffeine on Salmonella typhimurium and S. enteritidis survival in ground chicken breasts

The antimicrobial effect of roasted coffee filtrate (CF) and dicarbonyls on Salmonella Typhimurium and Salmonella Enteritidis in raw ground chicken breast meat (GCB) was investigated. Coffee was brewed and filtered before addition to GCB. Coffee filtrate with and without added caffeine, methylglyoxal, and/or glyoxal was added to GCB and then inoculated with Salmonella Typhimurium and Salmonella Enteritidis. Ground chicken samples were stomached with peptone water at days 1, 3, 5, and 7, plated on XLD agar with a TSA overlay, and Salmonella survivors were enumerated. CF alone gave less than a 1 Log reduction in all runs compared to control GCB with no treatment. Methylglyoxal (2.28 mg/g GCB) had the greatest antimicrobial effect against Salmonella Typhimurium and Salmonella Enteritidis in GCB with average Log reductions of 2.27 to 3.23, respectively, over the 7 d duration of the experiment compared to control GCB with no treatment. A 1 Log reduction was observed in GCB with CF, 0.93 mg glyoxal, and 1 mg caffeine/g chicken compared to the control and GCB with only CF. Heat-produced coffee compounds could potentially reduce Salmonella in retail ground chicken and chicken products.     

Evaluation of a capillary immunoassay system for detection of Salmonella typhimurium in poultry products

A capillary immunoassay system was constructed and optimized for detection of Salmonella Typhimurium. The system consisted of a capillary bioseparator-bioreactor and a flow-injection electrochemical detector. Three methods were compared for immobilizing antibodies on the inner surface of silica capillary columns; these methods were based on the use of a homobifunctional cross-linker glutaraldehyde, a heterobifunctional cross-linker N-succinimidyl-4-maleimidobutyrate, and biotin-streptavidin chemistry, respectively. The glutaraldehyde method gave the best reproducibility with a relative standard deviation of 1 to 6% for detection of Salmonella Typhimurium. The optimized immunoassay system could detect Salmonella Typhimurium in chicken breast and ground turkey meats with a detection limit of 2.4 x 10(3) and 2.4 x 10(4) CFU/ml, respectively. The total detection time was less than 2.5 h without any preenrichment. When stored at 4 degrees C, the immunocolumns could retain their activities for at least 3 months.     

A rapid most-probable-number-based enzyme-linked immunosorbent assay for the detection and enumeration of Salmonella Typhimurium in poultry wastewater

The rapid and accurate detection and enumeration of low levels of Salmonella Typhimurium in food processing facilities are critical components of an effective hazard analysis critical control point program. The objective of this study was to develop a rapid (8 h) most probable number (MPN)-enzyme-linked immunosorbent assay (ELISA) for the detection and enumeration of Salmonella Typhimurium in wastewater. The specific objectives were to (i) characterize poly- and monoclonal Salmonella Typhimurium-specific antibodies in order to select the most specific and sensitive antibody for Salmonella Typhimurium detection, and (ii) validate the MPN assay through a correlation between the 8-h MPN-ELISA and the traditional 48-h Salmonella Typhimurium MPN method in poultry scald water. Poultry scald water samples were spiked with 10 and 50 CFU/ml of Salmonella Typhimurium. The traditional MPN method used a 48-h enrichment period followed by an analysis, while the MPN-ELISA used a 5-h enrichment period followed by a 3-h ELISA analysis. No differences (P < 0.05) were found between the traditional MPN and the MPN-ELISA, indicating the promise of the MPN-ELISA for the rapid detection and enumeration of Salmonella Typhimurium within an 8-h shift. This abbreviated assay will permit increased product sampling and more rapid movement of food between production and processing, resulting in reduced spoilage and quality losses.     

Antibiotic resistance of Salmonella spp. from animal sources in Spain in 1996 and 2000

Emergence of resistant and multiresistant bacteria has become an important worldwide sanitary problem. International agencies recommend improving resistance surveillance studies in not only human but also animal origin strains. Because of its ubiquitous characteristics and zoonotic agent consideration, Salmonella spp. can be used as a good indicator microorganism for resistance surveillance studies. Salmonella spp. strains from animal sources isolated in 1996 (107) and 2000 (474) in Spain were tested against 12 different antimicrobials agents, using the disc diffusion method. Results were interpreted following the NCCLS criteria. Data showed that Salmonella spp. strains (61.7% in 1996 and 81.5% in 2000) were resistant to at least one antibiotic. Pig-related strains were considerably more resistant than strains from other sources. Enteritidis serotype was less resistant than other serotypes, except for ampicillin in 1996 (50% resistant) and nalidixic acid in 2000 (65.1% resistant). An emergent monophasic serotype, 4,5,12:i:-, first detected in 1997 in Spain was 100% resistant and 90% multiresistant. Typhimurium serotype was the most common Salmonella serotype from animal sources in both years. It was widely distributed among animals and was among the serotypes with a higher degree of resistance. The ampicillin, chloramphenicol, sulfonamides, streptomycin, and tetracycline resistance pattern, commonly associated with Salmonella serotype Typhimurium DT 104, had spread among other Typhimurium phage types and other Salmonella serotypes. Salmonella spp. strains isolated from feeding stuffs were considerably more susceptible than animal source strains, suggesting that the high Salmonella spp. resistance percentage was probably due to the use of antibiotics in animal farms rather than the consumption of contaminated feeding stuffs.