Phenotypic and genotypic profile of clinical and animal multidrug-resistant Salmonella enterica isolates from Mexico.

AIMS: The objective of this study was to obtain a phenotypic and genotypic profile of Salmonella enterica including multidrug-resistant (MDR) isolates from food-producing animals and clinical isolates, as well as their genetic relatedness in two different States of Mexico (Jalisco and State of Mexico). METHODS AND RESULTS: A total of 243 isolates were evaluated in terms of antimicrobial resistance (AMR) and related genes through a disk diffusion method and PCR respectively; we found 16 MDR isolates, all of them harbouring the blaCMY gene but not qnr genes, these isolates represent less than 10% of the collection. The pulsed-field gel electrophoresis revealed a higher genotypic similitude within isolates of State of Mexico than Jalisco. CONCLUSIONS: A low percentage of Salmonella isolates were resistant to relevant antibiotics in human health, nevertheless, the AMR and involved genes were similar despite the different serovars and origin of the isolates. SIGNIFICANCE AND IMPACT OF THE STUDY: This investigation provided an insight of the current status of AMR of Salmonella isolates in two States of Mexico and pinpoint the genes involved in AMR and their epidemiological relationship, the information could help to determine an adequate therapy in human and veterinary medicine.

Identification of a Hemagglutinin from Gallibacterium anatis.

Gallibacterium anatis has the ability to hemagglutinate rabbit erythrocytes; however, no bacterial component has yet been associated with this function. In the present work, a protein of approximately 65 kDa with hemagglutinating activity for glutaraldehyde-fixed chicken erythrocytes was purified by ion interchange chromatography from G. anatis F149(T) secreted proteins. The protein was recognized by a rabbit polyclonal serum against a hemagglutinin from Avibacterium paragallinarum. The 65 kDa purified protein presented identity with a G. anatis filamentous hemagglutinin by mass spectrometric analysis. As well, the bacterial surface of G. anatis was labeled by immune gold assays using a polyclonal serum against the 65-kDa protein. A similar protein was recognized in four other G. anatis strains by immunoblots using the same antiserum. The protein binds sheep or pig biotinylated fibrinogen, suggesting an interaction with basement membrane eukaryotic cells components, and the protein is present in G. anatis biofilms. Overall, the results suggest that the 65 kDa hemagglutinin is a common antigen and a potential virulence factor in G. anatis.

Protection Conferred by Infectious Coryza Vaccines Against Emergent Avibacterium paragallinarum Serovar C-1.

Infectious coryza is an upper respiratory disease of chickens caused by Avibacterium paragallinarum. Outbreaks of infectious coryza caused by Av. paragallinarum serovar C-1 isolates in coryza-vaccinated flocks in Ecuador and Mexico have been reported. In the current study, the protection conferred by four commercially available, trivalent infectious coryza vaccines in chickens challenged with a serovar C-1 isolate from an apparent coryza vaccine failure in a layer flock in Mexico was evaluated. Only one infectious coryza vaccine provided a good protection level (83%) in vaccinated chickens. These results might explain the infectious coryza outbreaks in vaccinated flocks that have been observed in the field.

Genotyping, pathogenicity, and immunogenicity of Avibacterium paragallinarum serovar B-1 isolates from the Americas.

The bacterium Avibacterium paragallinarum is the etiologic agent of infectious coryza of chickens. Among the nine Kume serovars currently recognized in this bacterium, serovar B-1 is a common serovar in the Americas. In the current study, serovar B-1 isolates from Ecuador (seven isolates), Mexico (seven isolates) and Panama (two isolates) were genotyped. In addition one Panamanian, one Ecuadorian, and two Mexican isolates were used in a vaccination-challenge trial in which the vaccine was based on the 2671 serovar B-1 reference strain. Genotyping by enterobacterial repetitive intergenic consensus-based PCR (ERIC-PCR) resulted in ten distinguishable ERIC patterns for the 16 isolates and the two reference strains of Av. paragallinarum included in the study. No ERIC patterns were shared among isolates of the three different countries. In the vaccination-challenge trial, one isolate from Panama showed a significantly lower virulence than did the three other isolates. In terms of cross-protection, chickens vaccinated with reference strain 2671 and challenged with an Ecuadorian strain showed 40% protection, a significantly lower protection than the homologous protection level. The other three field isolates gave a similar protection level to the homologous challenge.

Phylogenetic relationship of serovar C-1 isolates of Avibacterium paragallinarum.

The bacterium Avibacterium paragallinarum is the etiologic agent of infectious coryza of chickens. Serovar C-1 has emerged in infectious coryza outbreaks in layer hens of Ecuador and Mexico. In the current study, genotyping and phylogenetic analyses of five Ecuadorian and 10 Mexican isolates of Av. paragallinarum serovar C-1 were performed. All 15 isolates share a unique enterobacterial repetitive intergenic consensus-based-PCR fingerprint and have identical 16S ribosomal RNA and hemagglutinin antigen gene sequences. Results indicate that Ecuadorian and Mexican isolates of serovar C-1 of Av. paragallinarum have a clonal relationship.

Eimeria erythrorhynchosi n. sp. (Apicomplexa: Eimeriidae) from the American white pelican Pelecanus erythrorhynchos Gmelin, 1789 (Pelecaniformes: Pelecanidae) in Toluca, Mexico.

A new coccidian species, Eimeria erythrorhynchosi n. sp. (Apicomplexa: Eimeriidae) collected from the American white pelican Pelecanus erythrorhynchos Gmelin 1789, is reported from Toluca city, Mexico. Sporulated oocysts of the new species are ovoidal, 17.5-19.6 × 14.1-14.8 (18.5 × 14.5) µm, with a length/width (L/W) ratio of 1.0-1.5 (1.25); micropyle present, robust and protruding, W: 4.5-5.5, and polar body (1 or 2), L × W: 2.5 (2-3), associated with the micropyle; oocyst residuum absent. Sporocysts are ovoidal, 10.1-11.2 × 6.4-7.1 (10.7 × 6.8) µm, with a length/width (L/W) ratio of 1.0-1.6 (1.3); Stieda and sub-Stieda bodies are both present, but para-Stieda body is absent; sporocyst residuum of diffuse granules. Sporozoites are vermiform, 9.6 × 2.4 µm. The new species is the seventh species of Eimeria recorded in Pelecaniformes and the third in Pelecanidae.

ERIC-PCR genotyping of emergent serovar C-1 isolates of Avibacterium paragallinarum from Mexico.

Between 2008 and 2010, 14 isolates of Avibacterium paragallinarum were identified as serovar C-1 in Mexico. All isolates were obtained from commercial laying hens suffering infectious coryza despite a history of vaccination. The enterobacterial repetitive intergenic consensus-based PCR genotyping showed that all isolates had a common pattern. Until recently, serovars A-1, A-2, B-1, and C-2 were the serovars prevalent in Mexico. Serovar C-1 has been identified in Japan and recently in the Americas in Ecuador. Our current study suggests that Av. paragallinarum serovar C-1 is an emerging serovar in Mexico. Our results also indicate that the Mexican isolates of Av. paragallinarum serovar C-1 may have a clonal relationship. Knowledge of the genetic diversity of Av. paragallinarum may be of value in understanding vaccine performance and identifying the best combination to achieve broader protection.

Identification of Avibacterium paragallinarum serovar B-1 from severe infectious coryza outbreaks in Panama.

The isolation and identification of Avibacterium paragallinarum serovar B-1 from severe infectious coryza outbreaks in broiler breeders in Panama is reported for the first time. Infectious coryza was absent for over a decade in the breeder farms area. Disease outbreaks were characterized by an up to 45% drop in egg production and increased mortality. Use of a commercial trivalent bacterin and a strengthened biosecurity program prevented outbreaks in susceptible flocks in the farm.

Histopathologic findings in chickens experimentally infected with Gallibacterium anatis by nasal instillation.

Histologic findings in chickens experimentally infected by nasal instillation with reference strains of Gallibacterium anatis are described. No clinical signs were observed in experimentally infected birds; however, sequential histologic examinations of trachea, lung, air sacs, and liver revealed lesions in all infected chickens. Our observations suggest that the reference strains of G. anatis used in this experiment are capable of causing primary infection in chickens. Despite that the experimental birds were inoculated by intranasal route, lesions were detected in the liver, suggesting a probable bacteremia. Because several degrees of severity were established in histopathologic lesions, probable variations in virulence, among the experimental strains, also are discussed.

Cystoisospora felis infection in a captive jaguar cub (Panthera onca) in Michoacán, México.

Cystoisospora felis (Wenyon 1923) was identified in a 3-month-old, captive jaguar (Panthera onca) presenting with signs of gastrointestinal distress. The cub was fed beef, chicken, and commercial diet. Examination of fresh feces detected large (47.8 µm × 35 µm) unsporulated oocysts. Sporulated oocysts contained 2 sporocysts, each with 4 sporozoites. Oocyst morphometrics agreed with published features of C. felis described from domestic felines. Partial mitochondrial cytochrome c oxidase subunit I (mtCOI) gene was PCR-amplified and sequenced; the resulting sequence showed 100% identity to a C. felis isolate from a domestic cat. This is the first molecularly confirmed report of C. felis infecting and producing clinically evident, enteric disease in a jaguar cub.

Hemagglutinating activity of Gallibacterium strains.

In the present study, the hemagglutinating activity of seven reference strains, and nine Mexican and three Danish field isolates, of Gallibacterium was investigated by using fresh erythrocytes of 19 different types including chicken (broiler, rooster, layer hen), turkey, pigeon, quail, duck, Harris's hawk (Parabuteo unicinctus), house finch (Carpodacus mexicanus), cow, sheep, horse, dog, rabbit, pig, and human (groups A, B, AB, and O; Rh+). Agglutination was observed for broiler chicken, layer hen, quail, rabbit, and pig erythrocytes with a subset of Gallibacterium strains, whereas most tested strains agglutinated rabbit erythrocytes. Transmission electron microscopic examination of a hemagglutinating strain demonstrated a close interaction between the bacterial and erythrocyte surfaces. The results indicate that some Gallibacterium strains are able to agglutinate avian or mammalian erythrocytes, or both. However, the mechanisms enabling hemagglutination are not known and will be addressed in future studies.

The canary Serinus canaria (Passeriformes: Fringillidae) as a new host for Isospora bioccai in Mexico.

Isospora bioccai (Cringoli and Quesada 1991) (Protozoa, Apicomplexa, Eimeriidae) is reported and described from captive canaries Serinus canaria forma domestica (Linnaeus 1758) in Mexico. The oöcysts are subspherical, 25.5 × 23.5 µm, with smooth, bilayered wall, ∼1.3 µm thick. Micropyle absent, oöcyst residuum absent, and polar granule present, 4-8 rice-grain-shaped. Sporocysts are ovoidal, 16.7 × 10.5 µm. Stieda body knob-like and substieda body trapezoidal of irregular base. Sporocyst residuum is composed of granules of different sizes. Sporozoites are vermiform with one refractile body and a nucleus. Gamogony was seen in the duodenum. In addition to new locality, this is the first description of I. bioccai from S. canaria.

Antimicrobial Sensitivity of Avibacterium paragallinarum Isolates from Four Latin American Countries.

The antimicrobial sensitivity of 11 reference strains and 66 Avibacterium paragallinarum isolates from four Latin American countries was investigated. All 11 reference strains were sensitive to amoxicillin-clavulanic acid, ampicillin, fosfomycin, gentamicin, kanamycin, neomycin, penicillin, tetracycline, and trimethoprim-sulfamethoxazole. The 11 reference strains were all resistant to lincomycin. All isolates (100%) from Mexico, Panama, and Peru were sensitive to amoxicillin-clavulanic acid, ampicillin, and fosfomycin. The Ecuadorian isolates showed some level of resistance to all 16 agents tested. The Ecuadorian isolates were significantly more sensitive to erythromycin, lincomycin, and streptomycin, and significantly more resistant to gentamicin, kanamycin, penicillin, and tetracycline, than the Mexican isolates. A total of 57.5% (38/66) of tested isolates were multi-drug resistant (MDR), with 16 MDR patterns detected in 88.4% (23/26) of the antimicrobial-resistant isolates from Ecuador, and 8 MDR patterns detected in 42.8% (15/35) of the antimicrobial-resistant isolates from Mexico. In conclusion, the variation in antimicrobial sensitivity patterns between isolates from Ecuador and Mexico emphasizes the importance of active, ongoing monitoring of A. paragallinarum isolates.

Virulence of Serovar C-1 Strains of Avibacterium paragallinarum.

The bacterium Avibacterium paragallinarum is the etiologic agent of infectious coryza of chickens. There are nine serovars of A. paragallinarum , and serovar C-1 has emerged in outbreaks of infectious coryza in layer hens in the Americas, with all isolates having been obtained from infectious coryza-vaccinated chickens. In the current study, the clinical and histopathologic outcomes of experimental infections in chickens with A. paragallinarum of serovar C-1 were investigated. The Japanese serovar reference strain, H-18, and a Mexican isolate, ESV-135, were included in the study. No differences in clinical sign scores or morbidity were observed between the two strains. The two bacterial strains caused microscopic lesions of lymphoplasmacytic inflammation in the mucosa of the nasal cavity, infraorbital sinus, and trachea. Similar severe lesions were observed in birds inoculated with both H-18 and ESV-135 strains. The lesions were present 48 hr after inoculation and persisted until day 10 after inoculation. Slight to severe, extensive hemorrhages were observed in the lumen, mucous membranes, and lamina propria of the nasal cavity and infraorbital sinus in most of the chickens inoculated with either the reference strain H-18 or the ESV-135 isolate. Hemorrhages in the upper respiratory tract of chickens experimentally infected with A. paragallinarum are reported here for the first time. The results have confirmed the high virulence of the reference strain H-18 as previously reported and have shown that the Mexican isolate was as virulent as the reference strain. The virulence of A. paragallinarum isolates may play a role in explaining why severe infectious coryza outbreaks are being seen in both vaccinated and nonvaccinated chicken flocks.

Coinfection of Avibacterium paragallinarum and Ornithobacterium rhinotracheale in Chickens from Peru.

The coinfection of Avibacterium paragallinarum and Ornithobacterium rhinotracheale in two outbreaks of infectious coryza from Peru is reported. The diagnosis was confirmed by bacteriologic isolation, PCR testing, and sequencing of the 16S rRNA gene. The susceptibility of the isolates to 12 antimicrobial agents was tested by a disk diffusion method. The isolates were susceptible to amoxicillin/clavulanic acid and florfenicol and were resistant to oxacillin and sulfamethoxazole/trimethoprim. The coinfection of Av. paragallinarum and O. rhinotracheale and the severity of clinical signs were evaluated by experimental infection of specific-pathogen-free chickens. The group inoculated with O. rhinotracheale alone presented minimal clinical signs in 3 of 10 chickens. However, the groups inoculated with both Av. paragallinarum and O. rhinotracheale induced the most-severe clinical signs compared with the group inoculated with Av. paragallinarum alone. In conclusion, coinfections with Av. paragallinarum and O. rhinotracheale may occur, and these outbreaks could be more severe than single infections. Hence, the prevention, control, and diagnosis of Av. paragallinarum with O. rhinotracheale are important in outbreaks of infectious coryza.

Caryospora neofalconis and other enteroparasites in raptors from Mexico.

A coprological survey of enteroparasites in raptors (60 Falconiformes) from Central Mexico is reported. Three samples contained coccidian unsporulated oocysts, one contained Eimeria sp., one contained trematode eggs and one contained capillarid and trematode eggs and Eimeria sp. After sporulation at the laboratory, oocysts from a Falco peregrinus were identified as Caryospora neofalconis. The phylogenetic analysis of the C. neofalconis (GenBank accession number KT037081) showed a close relationship to the Australian strain RY 2014 isolate 16710 (GenBank accession number KJ634019) of Caryospora daceloe, with 99.2% similarity. As far as we are aware, this is the first report of C. neofalconis in raptors from Mexico and the Americas.