Human Brucella canis Infection and Subsequent Laboratory Exposures Associated with a Puppy, New York City, 2012.

Human Brucella canis infection incidence is unknown. Most identified cases are associated with pet dogs. Laboratory-acquired infections can occur following contact with Brucella spp. We identified a paediatric B. canis case, the source and other exposed persons. A 3-year-old New York City child with fever and dyspnoea was hospitalized for 48 h for bronchiolitis. After her admission, blood culture grew B. canis, she was prescribed anti-microbials and recovered. B. canis was also isolated from blood of the child's pet dog; these isolates were genetically similar. The dog originated from an Iowa breeding facility which was quarantined after identification of the dog's infection. Additionally, 31 laboratory workers were exposed and subsequently monitored for symptoms; 15 completed post-exposure prophylaxis. To our knowledge, this is the first report strongly suggesting B. canis zoonotic transmission to a child in the United States, and highlights the need for coordinated control policies to minimize human illness.

Equine stomachs harbor an abundant and diverse mucosal microbiota.

Little is known about the gastric mucosal microbiota in healthy horses, and its role in gastric disease has not been critically examined. The present study used a combination of 16S rRNA bacterial tag-encoded pyrosequencing (bTEFAP) and fluorescence in situ hybridization (FISH) to characterize the composition and spatial distribution of selected gastric mucosal microbiota of healthy horses. Biopsy specimens of the squamous, glandular, antral, and any ulcerated mucosa were obtained from 6 healthy horses by gastroscopy and from 3 horses immediately postmortem. Pyrosequencing was performed on biopsy specimens from 6 of the horses and yielded 53,920 reads in total, with 631 to 4,345 reads in each region per horse. The microbiome segregated into two distinct clusters comprised of horses that were stabled, fed hay, and sampled at postmortem (cluster 1) and horses that were pastured on grass, fed hay, and biopsied gastroscopically after a 12-h fast (cluster 2). The types of bacteria obtained from different anatomic regions clustered by horse rather than region. The dominant bacteria in cluster 1 were Firmicutes (>83% reads/sample), mainly Streptococcus spp., Lactobacillus spp. and, Sarcina spp. Cluster 2 was more diverse, with predominantly Proteobacteria, Bacteroidetes, and Firmicutes, consisting of Actinobacillus spp. Moraxella spp., Prevotella spp., and Porphyromonas spp. Helicobacter sp. sequences were not identified in any of 53,920 reads. FISH (n = 9) revealed bacteria throughout the stomach in close apposition to the mucosa, with significantly more Streptococcus spp. present in the glandular region of the stomach. The equine stomach harbors an abundant and diverse mucosal microbiota that varies by individual.

The prevalence of multidrug resistance is higher among bovine than human Salmonella enterica serotype Newport, Typhimurium, and 4,5,12:i:- isolates in the United States but differs by serotype and geographic region.

Salmonella represents an important zoonotic pathogen worldwide, but the transmission dynamics between humans and animals as well as within animal populations are incompletely understood. We characterized Salmonella isolates from cattle and humans in two geographic regions of the United States, the Pacific Northwest and the Northeast, using three common subtyping methods (pulsed-field gel electrophoresis [PFGE], multilocus variable number of tandem repeat analysis [MLVA], and multilocus sequence typing [MLST]). In addition, we analyzed the distribution of antimicrobial resistance among human and cattle Salmonella isolates from the two study areas and characterized Salmonella persistence on individual dairy farms. For both Salmonella enterica subsp. enterica serotypes Newport and Typhimurium, we found multidrug resistance to be significantly associated with bovine origin of isolates, with the odds of multidrug resistance for Newport isolates from cattle approximately 18 times higher than for Newport isolates from humans. Isolates from the Northwest were significantly more likely to be multidrug resistant than those from the Northeast, and susceptible and resistant isolates appeared to represent distinct Salmonella subtypes. We detected evidence for strain diversification during Salmonella persistence on farms, which included changes in antimicrobial resistance as well as genetic changes manifested in PFGE and MLVA pattern shifts. While discriminatory power was serotype dependent, the combination of PFGE data with either MLVA or resistance typing data consistently allowed for improved subtype discrimination. Our results are consistent with the idea that cattle are an important reservoir of multidrug-resistant Salmonella infections in humans. In addition, the study provides evidence for the value of including antimicrobial resistance data in epidemiological investigations and highlights the benefits and potential problems of combining subtyping methods.

Antimicrobial resistance impacts clinical outcome of granulomatous colitis in boxer dogs.

BACKGROUND: Escherichia coli have recently been identified within the colonic mucosa of Boxer dogs with granulomatous colitis (GC). Eradication of invasive E. coli is associated with clinical and histological remission. OBJECTIVES: To determine antimicrobial susceptibility profiles of E. coli strains from GC and healthy dogs, and the association of antimicrobial resistance with clinical outcome. ANIMALS: Fourteen Boxer dogs with GC and 17 healthy pet dogs. METHODS: Prospective study: E. coli was cultured from GC biopsies and rectal mucosal swabs of healthy dogs. Individual strains were selected by phylogroup and overall genotype, determined by triplex- and random amplified polymorphic DNA-polymerase chain reaction respectively. Antimicrobial susceptibility was determined by broth microdilution minimal inhibitory concentration. RESULTS: Culture yielded 23 E. coli strains from GC (1-3/dog, median 2) and 34 strains from healthy (1-3/dog, median 2). E. coli phylogroups were similar (P=.18) in GC (5A, 7B1, 5B2, 6D) and healthy (2A, 10B1, 15B2, 7D). Resistance to ampicillin, amoxicillin-clavulanate, cefoxitin, tetracycline, trimethoprim-sulfa (TMS), ciprofloxacin, and chloramphenicol was greater (P<.05) in GC (21-64%) than healthy (0-24%). Enrofloxacin resistant E. coli were isolated from 6/14 GC versus 0/17 healthy (P=.004). Of the enrofloxacin resistant cases, 4/6 were also resistant to macrophage-penetrating antimicrobials such as chloramphenicol, rifampicin, and TMS. Enrofloxacin treatment before definitive diagnosis was associated with antimicrobial resistance (P<.01) and poor clinical outcome (P<.01). CONCLUSIONS AND CLINICAL IMPORTANCE: Antimicrobial resistance is common among GC-associated E. coli and impacts clinical response. Antimicrobial therapy should be guided by mucosal culture and antimicrobial susceptibility testing rather than empirical wisdom.

Salmonella enterica serotype 4,5,12:i:-, an emerging Salmonella serotype that represents multiple distinct clones.

The prevalence, among human clinical cases, of Salmonella enterica serotype 4,5,12:i:-, a serotype antigenically similar to Salmonella enterica serotype Typhimurium but lacking second-phase flagellar antigens, has increased considerably over the last 10 years. To probe the evolution and ecology of this emerging serotype, we characterized 190 Salmonella isolates initially classified as Salmonella serotypes 4,5,12:i:- (n = 90) and Typhimurium (n = 100) and obtained from various sources in the United States and Spain. These isolates were characterized into six sequence types (determined by multilocus sequence typing [MLST]) and 79 pulsed-field gel electrophoresis types. The majority of Salmonella serotype 4,5,12:i:- and Typhimurium isolates (85 and 84 isolates, respectively) represented a single MLST type. Existing genome information revealed different genome deletions (which included genes responsible for phase 2 flagellum expression) in four Spanish Salmonella serotype 4,5,12:i:- isolates and one U.S. Salmonella serotype 4,5,12:i:- isolate. Fifty-nine isolates of both serotypes, representing different sources and geographical locations as well as different molecular subtypes, were thus screened for the presence of six genes and one specific region, all of which were previously found to show variable presence among Salmonella serotype 4,5,12:i:- and Typhimurium strains. All Salmonella serotype 4,5,12:i:- isolates lacked the phase 2 flagella genes fljA and fljB, which were present in all Salmonella serotype Typhimurium isolates. While all Spanish Salmonella serotype 4,5,12:i:- isolates carried the same deletion surrounding fljAB, all but two U.S. isolates showed a different genomic deletion; the two atypical U.S. isolates represented the "Spanish" deletion genotype and a unique deletion genotype. Salmonella serotype 4,5,12:i:- thus appears to represent at least two common clones, which cannot easily be differentiated with standard diagnostic procedures.

The duration of fecal Salmonella shedding following clinical disease among dairy cattle in the northeastern USA.

The objectives of this study were to determine the duration of fecal Salmonella shedding among dairy cattle in the northeastern United States following laboratory-confirmed clinical disease and to evaluate whether age group or serotype was associated with either shedding period or mortality. Study farms included 22 dairy herds that had at least two previous salmonellosis cases confirmed by fecal culture. Veterinarians continued to submit culture samples from clinical suspects following herd enrollment, and fecal samples from positive cattle were collected monthly until three sequential negative results were obtained or until loss to follow-up. There were 357 culture-positive clinical cases that each involved a single serotype during the shedding period. The Kaplan-Meier median duration of fecal Salmonella shedding was 50 days, and the maximum was 391 days. S. Newport was the predominant serotype, accounting for 51% of the cases. Age group and serotype were not significant predictors of Salmonella shedding duration in a Cox proportional hazards model, when stratifying by herd. However, the proportion of adult cows shedding for at least two consecutive monthly samples was significantly greater than the proportion of female calves shedding for this duration (Fisher's exact test p-value<0.01). Age group was also associated with mortality in this study; calves with salmonellosis were more likely to die than cows as estimated by a logistic regression model which controlled for herd as a random effect (p-value=0.04).

The incidence of salmonellosis among dairy herds in the northeastern United States.

The objectives of this study were to estimate the incidence of salmonellosis among a large sample of dairy herds in the northeastern United States (both at the animal level and the herd level), to describe the serotypes and antimicrobial resistance profiles of the positive samples, and to determine whether various herd-level factors were important predictors of incidence. Participating veterinarians enrolled 831 dairy herds and submitted fecal samples from 2,565 female dairy cattle for Salmonella culture because of suspicion of clinical disease. Estimates of animal-level incidence rates were calculated for each age group as the number of cases per animal time at risk, and an estimate of herd-level incidence rate was calculated as the number of positive herds per herd time at risk. Descriptive analysis of serotype data and level of antimicrobial resistance was performed, and Poisson regression analysis was used to study associations between the within-herd incidence of salmonellosis and certain predictor variables (herd size, housing type, vaccination status, and prior history of Salmonella infection). Salmonella was isolated from 576 (22.5%) samples representing 93 herds. The animal-level incidence rates for preweaned female calves, heifers, and adult cows were 8.1, 0.04, and 1.8 cases per 1,000 animal-years, respectively. The herd-level incidence rate was 8.6 positive herds per 100 herd-years. Salmonella Newport was the predominant serotype, accounting for 41% of the cases, followed by Salmonella Typhimurium. Over 68% of all isolates were resistant to 5 or more antimicrobial agents. Herd size was the only significant predictor of the incidence of salmonellosis in a multivariable model; herds with at least 400 female dairy cattle had a higher incidence rate than smaller herds. Our results shed light on the impact of salmonellosis on the dairy industry in the northeastern United States, and they help clarify the role of dairy cattle as a source of Salmonella serotypes that are also important human pathogens.

The relationship of mucosal bacteria to duodenal histopathology, cytokine mRNA, and clinical disease activity in cats with inflammatory bowel disease.

Feline inflammatory bowel disease (IBD) is the term applied to a group of poorly understood enteropathies that are considered a consequence of uncontrolled intestinal inflammation in response to a combination of elusive environmental, enteric microbial, and immunoregulatory factors in genetically susceptible cats. The present study sought to examine the relationship of mucosal bacteria to intestinal inflammation and clinical disease activity in cats with inflammatory bowel disease. Duodenal biopsies were collected from 27 cats: 17 undergoing diagnostic investigation of signs of gastrointestinal disease, and 10 healthy controls. Subjective duodenal histopathology ranged from normal (10), through mild (6), moderate (8), and severe (3) IBD. The number and spatial distribution of mucosal bacteria was determined by fluorescence in situ hybridization with probes to 16S rDNA. Mucosal inflammation was evaluated by objective histopathology and cytokine profiles of duodenal biopsies. The number of mucosa-associated Enterobacteriaceae was higher in cats with signs of gastrointestinal disease than healthy cats (P<0.001). Total numbers of mucosal bacteria were strongly associated with changes in mucosal architecture (P<0.001) and the density of cellular infiltrates, particularly macrophages (P<0.002) and CD3(+)lymphocytes (P<0.05). The number of Enterobacteriaceae, E. coli, and Clostridium spp. correlated with abnormalities in mucosal architecture (principally atrophy and fusion), upregulation of cytokine mRNA (particularly IL-1, -8 and -12), and the number of clinical signs exhibited by the affected cats. These data establish that the density and composition of the mucosal flora is related to the presence and severity of intestinal inflammation in cats and suggest that mucosal bacteria are involved in the etiopathogenesis of feline IBD.

Association of Helicobacter with cholangiohepatitis in cats.

Infection with Helicobacter spp. is increasingly linked with hepatobiliary inflammation and neoplasia in people and in a variety of animals. We sought to determine if Helicobacter species infection is associated with cholangiohepatitis in cats. Deoxyribonucleic acid was extracted from tissue blocks from cats with cholangiohepatitis (32), noninflammatory liver disease (13), and cats with normal liver histology (4). Deoxyribonucleic acid was polymerase chain reaction-amplified with 2 sets of Helicobacter genus-specific primers, gel purified, and sequenced. Polymerase chain reaction-positive hepatic tissue was further examined with Steiner's stain, immunocytochemistry for Helicobacter species, and eubacterial fluorescent in situ hybridization. Gastric tissues of cats with known Helicobacter infection status served as controls for deoxyribonucleic acid extraction and sequence comparison. Helicobacter species were detected in 2/32 cats with cholangiohepatitis, and 1/17 controls. Sequences had 100% identity with Helicobacter species liver, Helicobacter pylori, and Helicobacter fenelliae/cinaedii in a cat with suppurative cholangitis, Helicobacter species liver, Helicobacter pylori, and Helicobacter nemistrineae in a cat with mild lymphocytic portal hepatitis, and Helicobacter bilis in a cat with portosystemic vascular anomaly. In contrast, sequences from gastric biopsies showed highest homology (99-100%) to "Helicobacter heilmannii," Helicobacter bizzozeronii, Helicobacter felis, and Helicobacter salomonis. Fluorescent in situ hybridization revealed a semicurved bacterium, with Helicobacter-like morphology, in an intrahepatic bile duct of the cat with suppurative cholangitis. This study has identified Helicobacter deoxyribonucleic acid in 2/32 cats with cholangiohepatitis and 1/13 cats with noninflammatory liver disease. Deoxyribonucleic acid sequences of hepatic Helicobacter species were distinct from those found in the stomach and are broadly consistent with those identified in cat intestine and bile, and hepatobiliary disease in people and rodents.

Ecology and transmission of Listeria monocytogenes infecting ruminants and in the farm environment.

A case-control study involving 24 case farms with at least one recent case of listeriosis and 28 matched control farms with no listeriosis cases was conducted to probe the transmission and ecology of Listeria monocytogenes on farms. A total of 528 fecal, 516 feed, and 1,012 environmental soil and water samples were cultured for L. monocytogenes. While the overall prevalence of L. monocytogenes in cattle case farms (24.4%) was similar to that in control farms (20.2%), small-ruminant (goat and sheep) farms showed a significantly (P < 0.0001) higher prevalence in case farms (32.9%) than in control farms (5.9%). EcoRI ribotyping of clinical (n = 17) and farm (n = 414) isolates differentiated 51 ribotypes. L. monocytogenes ribotypes isolated from clinical cases and fecal samples were more frequent in environmental than in feed samples, indicating that infected animals may contribute to L. monocytogenes dispersal into the farm environment. Ribotype DUP-1038B was significantly (P < 0.05) associated with fecal samples compared with farm environment and animal feedstuff samples. Ribotype DUP-1045A was significantly (P < 0.05) associated with soil compared to feces and with control farms compared to case farms. Our data indicate that (i) the epidemiology and transmission of L. monocytogenes differ between small-ruminant and cattle farms; (ii) cattle contribute to amplification and dispersal of L. monocytogenes into the farm environment, (iii) the bovine farm ecosystem maintains a high prevalence of L. monocytogenes, including subtypes linked to human listeriosis cases and outbreaks, and (iv) L. monocytogenes subtypes may differ in their abilities to infect animals and to survive in farm environments.

Effect of previous antimicrobial treatment on fecal shedding of Salmonella enterica subsp. enterica serogroup B in New York dairy herds with recent clinical salmonellosis.

The association of herd- and sample-level factors with the isolation of Salmonella group B from cattle fecal samples was analyzed. Study farms were 65 dairy herds with a recent history of laboratory-confirmed clinical salmonella infections. Herds were visited once per month for three months to collect data and samples for bacteriological culture. Herd size varied widely from 34 to 3700 total cattle on the farm (median=370). Salmonella serogroup B was isolated from 270 of 2726 samples tested. The predominant serotypes identified were S. Typhimurium and S. Typhimurium var. Copenhagen. Logistic regression was used to analyze the relationship between potential risk factors and isolating Salmonella serogroup B. The only herd-level factor which was significantly associated with fecal shedding was total herd size (hundreds of cattle OR=1.09; 95% confidence interval (CI): 1.05, 1.14). The probability of a positive sample decreased substantially for longer intervals between the initial clinical case and sampling (interval in months OR=0.5; 95% CI: 0.3, 0.6). The presence of diarrhea increased the risk of shedding (OR=2.1; 95% CI: 1.4, 3.0). The effect of recent treatment with antimicrobial agents depended on age group. For heifers and cows, recent antimicrobial treatment increased the probability of isolating Salmonella (heifers OR=11.8; 95% CI: 2.9, 48.8; cows OR=4.1; 95% CI: 2.0, 8.4), but this effect was not statistically significant for calves before weaning. Among animals without recent antimicrobial treatment, preweaned calves were more likely to have positive samples than cows (OR=3.5; 95% CI: 1.8, 6.9; heifers OR=4.7; 95% CI: 2.3, 9.6).

Farm-management and milking practices associated with the presence of Listeria monocytogenes in New York state dairy herds.

Knowledge of the relationship between dairy herd management and milking practices with the occurrence of Listeria monocytogenes on dairy farms might assist in the development of intervention strategies aimed at eliminating this organism at the pre-harvest dairy-food-production level. This paper represents a first step towards that goal. We carried out a cross-sectional study to identify farm factors that were associated with isolation of L. monocytogenes from on-farm in-line milk-filters. Data on these factors were collected by personal interview of the farm owners or managers. Logistic regression was used to evaluate the significance of association of each factor while simultaneously controlling for the presence of other factors. A systematic approach was developed in which the bivariable association of the hypothesized factors initially was evaluated. All significant factors were then jointly evaluated in a multivariable logistic model. Farms that used a bucket system had significantly higher odds of L. monocytogenes as compared to farms that used a round-the-barn pipeline milking system (OR=0.35,P=0.05) or milking parlor (OR=0.21,P=0.01). There was a significant association between pre-milking teat disinfection (OR=0.26,P=0.001) and pre-milking examination of abnormal appearance of milk (OR=0.4,P=0.01) against the occurrence of L. monocytogenes. We also found a significant association between the use of E. coli J5 vaccine (OR=3.3,P=0.03) and how long dry-cow therapy had been used on farm (OR=0.34,P=0.04).

Helicobacter pylori infection in the cat: evaluation of gastric colonization, inflammation and function.

BACKGROUND: Further elucidation of the consequences of Helicobacter pylori infection on gastric mucosal inflammation and gastric secretory function would be facilitated by an animal model that is susceptible to infection with H. pylori, is broadly similar in gastric physiology and pathology to people, and is amenable to repeated non-invasive evaluation. The goal of this study was to examine the interrelationship of bacterial colonization, mucosal inflammation and gastric secretory function in cats with naturally acquired H. pylori infection. MATERIALS AND METHODS: Twenty clinically healthy cats with naturally acquired H. pylori infection (cagA-, picB) and 19 Helicobacter-free cats were evaluated. Gastric colonization was determined by tissue urease activity, light microscopy, culture and PCR. The mucosal inflammatory response was evaluated by light microscopy, and by RT-PCR of the pro-inflammatory cytokines IL-1alpha, IL-1beta, IL-8 and TNF-alpha in gastric mucosa. Gastric secretory function was assessed by measuring pentagastrin-stimulated acid secretion, fasting plasma gastrin, and antral mucosal gastrin and somatostatin immunoreactivity. RESULTS: H. pylori colonized the pylorus, fundus and cardia in similar density. Bacteria were observed free in the lumen of gastric glands and were also tightly adherent to epithelial cells where they were associated with microvillus effacement. Mononuclear inflammation, lymphoid follicle hyperplasia, atrophy and fibrosis were observed primarily in H. pylori-infected cats, with the pylorus most severely affected. Neutrophilic and eosinophilic infiltrates, epithelial dysplasia, and up-regulation of mucosal IL-1beta and IL-8 were observed solely in infected cats. Fasting plasma gastrin concentrations and pentagastrin-stimulated acid output were similar in both infected and uninfected cats. There was no relationship of bacterial colonization density or gastric inflammation to plasma gastrin concentrations or gastric acid output. CONCLUSIONS: The pattern of colonization and the mucosal inflammatory response in cats with naturally acquired H. pylori are broadly similar to those in infected people, particularly children, and non-human primates. The upregulation of IL-8 in infected cats was independent of cagA and picB. Our findings argue against a direct acid-suppressing effect of H. pylori on the gastric secretory-axis in chronically infected cats.

A cross-sectional study on the prevalence of Listeria monocytogenes and Salmonella in New York dairy herds.

As part of our long-term objective of assessing risk for Listeria monocytogenes and Salmonella spp. in dairy herds, we carried out a cross-sectional study to determine the prevalence of the two organisms. The study population consisted of a sample of dairy herds enrolled in the Quality Milk Promotion Services at Cornell during the period of April 1998 to March 1999. The sample was stratified by geographical region to assure representation. Four hundred and four dairy farms were enrolled in the study. In-line milk filters were collected from each farm for bacteriological examination of L. monocytogenes and Salmonella spp. Four hypothesized risk factors were evaluated for their association with the likelihood of the presence of each of the two organisms using logistic regression analysis. Listeria monocytogenes was isolated from 51 (12.6%) of the milk filters. We found region-specific differences in the rate of farms with positive milk filters for this pathogen. Salmonella spp. were isolated from 6 (1.5%) milk filters. One isolate was confirmed as Salmonella enterica Serotype Typhimurium DT 104. There was no significant association between any of the hypothetical risk factors and the likelihood of Salmonella spp. isolation. Our study demonstrated that both L. monocytogenes and Salmonella spp. were prevalent in milk filters in New York dairy herds and that Salmonella was isolated at a significantly lower rate then L. monocytogenes.

Streptococcus didelphis sp. nov., a streptococcus with marked catalase activity isolated from opossums (Didelphis virginiana) with suppurative dermatitis and liver fibrosis.

beta-Haemolytic, catalase-positive, Gram-positive cocci that formed chains in broth media but did not react with Lancefield group antisera were isolated from skin lesions, spleen, liver and lungs of nine opossums, including eight from a research colony and one from a wildlife rehabilitation organization. The isolates had vigorous catalase activity that was retained on initial passage on non-blood-containing media, but this activity was lost in subsequent passages. The use of standard phenotypic tests did not lead to satisfactory identification of these organisms beyond the genus level, even if the aberrant catalase reaction was not considered. The 16S rRNA gene sequence of the isolates was most similar (96%) to Streptococcus dysgalactiae, but distinct from that species as 16S rRNA gene similarity of different strains of S. dysgalactiae was > 99%. Characterization of biochemical reactions and cell-wall fatty acid profiles also revealed significant differences between the opossum isolates and all other known Streptococcus spp., thus it is proposed as a new species with the name Streptococcus didelphis, sp. nov. The type strain is ATCC 700828T.

Diagnostic and public health dilemma of lactose-fermenting Salmonella enterica serotype Typhimurium in cattle in the Northeastern United States.

The presence of lactose-fermenting Salmonella strains in clinical case materials presented to microbiology laboratories presents problems in detection and identification. Failure to detect these strains also presents a public health problem. The laboratory methods used in detecting lactose-fermenting Salmonella enterica serotype Typhimurium from six outbreaks of salmonellosis in veal calves are described. Each outbreak was caused by a multiply-resistant and lactose-fermenting strain of S. enterica serotype Typhimurium. The use of Levine eosin-methylene blue agar in combination with screening of suspect colonies for C8 esterase enzyme and inoculation of colonies into sulfide-indole-motility medium for hydrogen sulfide production was particularly effective for their detection. A hypothesis for the creation of lactose-fermenting salmonellae in the environment is presented. It is proposed that the environment and husbandry practices of veal-raising barns provide a unique niche in which lactose-fermenting salmonellae may arise.

Prevalence of Escherichia coli O157:H7 from cull dairy cows in New York state and comparison of culture methods used during preharvest food safety investigations.

A number of protocols for the cultural detection of Escherichia coli O157:H7 in clinical fecal specimens have been proposed. In the present study direct plating of cattle feces was compared to three different broth enrichment protocols, i.e., a protocol with modified E. coli broth with novobiocin, a protocol with Trypticase soy broth with cefixime and vancomycin, and a protocol with Gram-Negative Broth with novobiocin, for their relative abilities to detect E. coli O157:H7 in feces. In all enrichment protocols, dilutions of the enrichment broths onto 150-mm sorbitol-MacConkey agar plates to which cefixime and tellurite were added were used along with reading of agar plates at both 24 and 48 h. Fecal samples came from a preharvest food safety project in which feces from New York cull dairy cattle from a northeastern packing plant along with experimentally inoculated adult dairy cow feces were tested. The performances of the broth enrichments were comparable to each other, but the broth enrichments were superior to direct plating in their ability to detect E. coli O157:H7. Regardless of the culture protocol used, recovery of E. coli O157:H7 is more likely from fresh fecal specimens than from frozen samples. An overall prevalence of E. coli O157:H7 fecal shedding by New York cull dairy cattle of 1.3% was found in specimens just before processing at the packing plant.

Helicobacter felis infection is associated with lymphoid follicular hyperplasia and mild gastritis but normal gastric secretory function in cats.

The relationship of Helicobacter felis, a bacterium observed in the stomachs of cats, to gastric disease is unclear. The objective of this study was to determine if H. felis infection alters gastric histopathology, proinflammatory cytokine expression, and secretory function and evokes a humoral immune response in cats. Five specific-pathogen-free (SPF) Helicobacter-free cats were studied before and for 1 year after oral inoculation with H. felis (ATCC 49179). Four SPF H. felis-uninfected cats served as controls. The stomachs of all five H. felis-inoculated cats became colonized, as determined by urease activity, histopathology, PCR, culture, and transmission electron microscopy of serial gastric biopsies at 0, 3, 5, 8, and 12 months. Uninoculated cats remained Helicobacter free. Lymphoid follicular hyperplasia, atrophy, and fibrosis were observed primarily in the pylorus of infected cats. Mild mononuclear inflammation was detected in both infected and uninfected cats, but was more extensive in infected cats, with pangastric inflammation, eosinophilic infiltrates, and cardia gastritis observed only in infected cats. No upregulation of antral mucosal interleukin 1alpha (IL-1alpha), IL-1beta, or tumor necrosis factor alpha was detected by reverse transcription-PCR in any cat. The gastric secretory axes, assessed by fasting plasma gastrin, antral mucosal gastrin and somatostatin immunoreactivity, and pentagastrin-stimulated gastric acid secretion, were similar in both infected and uninfected cats. Gradual seroconversion (immunoglobulin G) was observed in four of five infected cats, with enzyme-linked immunosorbent assay values reaching 4x to 12x baseline 12 months postinfection. These findings indicate that H. felis infection in cats induces lymphoid follicular hyperplasia, mild gastritis, and seroconversion, but is associated with normal gastric secretory function.

Gastric function in dogs with naturally acquired gastric Helicobacter spp. infection.

The association of Helicobacter pylori with gastritis, peptic ulcers, and gastric neoplasia has led to fundamental changes in the understanding of gastric disease in humans. The relationship of Helicobacter spp. infection to gastric disease in dogs is unclear. The objective of this study was to determine if Helicobacter infection affects the gastric secretory axis of dogs. Eight Beagle dogs with naturally acquired Helicobacter spp. infection were studied before and after (4 and 29 days) the attempted eradication of Helicobacter spp. with a combination of amoxicillin, metronidazole, and famotidine (AMF). Six specific-pathogen-free, Helicobacter-free Beagle dogs served as controls. The electron microscopic appearance of spiral organisms in infected dogs indicated coinfection with Helicobacter felis- and H bizzozeronii-like organisms. Unstimulated gastric pH and fasting, postprandial, and bombesin-stimulated plasma gastrin were similar in both infected and uninfected dogs, although a trend (P = .09) toward higher meal-stimulated gastrin was observed in infected dogs at 60 minutes. Pentagastrin-stimulated maximal acid output (mmol HCI/kg0.75/hour) and titratable acidity (mmol HCl/mL) were similar in both infected and uninfected dogs, but gastric pH during maximal acid output was lower (P < .01) in uninfected dogs. Mild gastric inflammation was present in both infected and uninfected dogs. Gastric spiral organisms were undetectable in 6/8 infected dogs 4 days after AMF but had recurred in 8/8 dogs 29 days after AMF. Analysis of gastric DNA with Helicobacter-specific primers indicated persistence of Helicobacter DNA at 4 and 29 days after antibiotic therapy. Acid secretion, plasma gastrin, and mucosal inflammation were not affected by the transient suppression of Helicobacter spp. by AMF. These findings suggest that gastric secretory function in dogs is not markedly perturbed by naturally acquired Helicobacter spp. infection and that treatment with amoxicillin, metronidazole, and famotidine causes suppression rather than eradication of gastric Helicobacter spp. in dogs.

Salmonella enterica serotype Dublin infection: an emerging infectious disease for the northeastern United States.

Salmonella enterica subspecies enterica serotype Dublin (S. enterica Dublin) emerged for the first time in New York, Pennsylvania, and Ohio in 1988. Since that time this host-adapted serotype has spread throughout the veal- and dairy beef-raising operations in the region; very few dairy farms have experienced clinical S. enterica Dublin infections. This study details the epidemiology of the outbreaks in cattle. During the period 1988 through 1995, nine New York and four Pennsylvania counties have been affected; 13 different locations were involved in New York, and 10 were involved in Pennsylvania. The morbidity and mortality and seasonal distribution of outbreaks, which totaled 35, is described. The antimicrobial susceptibility pattern of isolates revealed that many of the strains were resistant to a number of commonly used drugs. Clinical case details and pathology information are provided, with a caution to clinicians and microbiologists presented with suspect animals, i.e., most cases occurred in older calves, which is atypical for salmonellosis for this region (calves were 8 or more weeks old) and presented as pneumonia and septicemia rather than the primarily diarrheal syndrome that is more typically recognized for the region. The epidemiology of cases is analyzed through cluster analysis of bacterial isolates and their fatty acid methyl ester profiles; at least six clones appeared in the region during the study period. Results of the epidemiology analysis are used to support a hypothesis regarding the source of S. enterica Dublin for the region and its manner of dissemination.