SUMMARY. Control of pathogenic avian mycoplasmas can consist of one of three general approaches: Maintaining flocks free of infection, medication, or vaccination. Maintaining flocks free of pathogenic mycoplasmas consists of maintaining replacements from mycoplasma-free sources in a single-age, all-in all-out management system. Good biosecurity and an effective monitoring system are necessary aspects of this program. Medication can be very useful in preventing clinical signs and lesions, as well as economic losses, but cannot be used to eliminate infection from a flock and is therefore not a satisfactory long-term solution. Vaccination against Mycoplasma gallisepticum (MG) or M. synoviae (MS) can be a useful long-term solution in situations where maintaining flocks free of infection is not feasible, especially on multi-age commercial egg production sites.

https://bioone.org/journals/avian-diseases/volume-52/issue-3/8323-041808-Review.1/Control-of-Avian-Mycoplasma-Infections-in-Commercial-Poultry/10.1637/8323-041808-Review.1.pdf

Control of Avian Mycoplasma Infections in Commercial Poultry

Multidrug-resistant opportunistic pathogens have become endemic to the veterinary hospital environment. Escherichia coli isolates resistant to 12 antibiotics were isolated from two dogs that were housed in the intensive care unit at The University of Georgia Veterinary Teaching Hospital within 48 h of each other. Review of 21 retrospective and prospective hospital-acquired E. coli infections revealed that the isolates had similar antibiotic resistance profiles, characterized by resistance to most cephalosporins, β-lactams, and the β-lactamase inhibitor clavulanic acid as well as resistance to tetracycline, spectinomycin, sulfonamides, chloramphenicol, and gentamicin. E. coli isolates with similar resistance profiles were also isolated from the environment in the intensive care unit and surgery wards. Multiple E. coli genetic types were endemic to the hospital environment, with the pulsed-field gel electrophoresis fingerprint identified among E. coli isolates from diseased animals and the hospital environment matching. The extended-spectrum cephalosporin resistance in these nosocomial E. coli isolates was attributed to the cephamycinase-encoding gene, blaCMY2. Chloramphenicol resistance was due in part to the dissemination of the florfenicol resistance gene, flo, among these isolates. Resistance encoded by both genes was self-transmissible. Although blaCMY2 and flo were common to the polyclonal, nosocomial E. coli isolates, there was considerable diversity in the genetic compositions of class 1 integrons, especially among isolates belonging to the same genetic type. Two or more integrons were generally present in these isolates. The gene cassettes present within each integron ranged in size from 0.6 to 2.4 kb, although a 1.7-kb gene cassette was the most prevalent. The 1.7-kb gene cassette contained spectinomycin resistance gene aadA5 and trimethoprim resistance gene dfrA17.

/pdf/characterization-of-multidrug-resistant-escherichia-coli-5e6e6vp27s.pdf

Characterization of Multidrug-Resistant Escherichia coli Isolates Associated with Nosocomial Infections in Dogs

Four generic Mycoplasma gallisepticum (MG) polymerase chain reactions (PCRs) (16S rRNA PCR, three newly developed PCR methods that target surface protein genes [mgc2, LP (nested) and gapA (nested)]) were compared for analytical specificity and sensitivity and for diagnostic sensitivity (Se) and specificity of detection from tracheal swabs. The licensed MG DNA Test Kit Flock Chek test (IDEXX, Laboratories, Inc., Westbrook, ME) was as well evaluated for the diagnostic specificity and sensitivity of detection from tracheal swabs. Analytical specificity was evaluated for the four generic PCR methods using a panel of DNA samples from microorganisms that may be isolated from the trachea of commercial poultry and other fowl. PCR methods mgc2, nLP, and ngapA only amplified DNA from MG, whereas 16S rRNA PCR amplified DNA from MG and Mycoplasma imitans. The analytical sensitivity of the four generic PCR methods expressed in color-changing units (CCU)/amplification reaction was estimated for each PCR method...

Evaluation and Comparison of Various PCR Methods for Detection of Mycoplasma gallisepticum Infection in Chickens

Isolation of Mycoplasma hyopneumoniae from different sampling sites in experimentally infected and contact SPF piglets.

Mycoplasma synoviae is a major avian pathogen that synthesizes hemagglutinin VlhA, an abundant immunodominant surface lipoprotein. In most M. synoviae strains, the VlhA protein cleaves into the N-terminal part, a lipoprotein MSPB, and a C-terminal part MSPA, which mediates binding to erythrocytes. VlhA is encoded by the vlhA gene of which the 5′-end is present in the genome as a single copy, which does not change its sequence during recombination of the vlhA gene with pseudogenes. In this study, sequence analyses of the 5′-end vlhA sequences of 30 M. synoviae isolates revealed a highly polymorphic region encoding the proline-rich repeats (PRR) in the N-terminal part of MSPB. Pathogenic strain K1968 had an insertion encoding sequence DNPQNPN in PRR, whereas strains F10-2AS, K2581, K3344 and five strains belonging to two related clusters of strains isolated recently from chickens in Slovenia lacked one PRR repeat of 19 amino acids. The predicted length variations correlated well with the lengths of the corresponding MSPB proteins detected in immunoblots with specific antibodies. Comparison of the 5′-end vlhA sequences of 30 M. synoviae strains showed 11 different types of vlhA sequences indicating that the analysis of this vlhA part is useful for strain differentiation. Distinct sequence motifs seem to be characteristic for vlhA genes of individual M. synoviae strains or clusters of strains and can be used as markers for tracing their spreading between poultry farms.

Molecular basis of the length variation in the N-terminal part of Mycoplasma synoviae hemagglutinin.

Detection of Mycoplasma synoviae in poultry environment samples by culture and polymerase chain reaction

Comparison of pulsed-field gel electrophoresis with random amplified polymorphic DNA for typing of Mycoplasma synoviae.

The polymerase chain reaction (PCR) was used to detect Mycoplasma gallisepticum in samples collected from the environment of experimentally or naturally infected poultry. Culture was also used in the experimental infections. Of 160 samples of food, drinking water, feathers, droppings or dust collected during experimental infection, 103 were positive using a M. gallisepticum-specific PCR (MG-PCR) and 68 were positive using a PCR (mycoplasma-PCR) that detects all species of the genera Mycoplasma, Spiroplasma, Acholeplasma and Ureaplasma. Six of these samples were also positive by culture. In environmental samples collected on a depopulated M. gallisepticum-positive turkey farm, three and two out of a total of 12 were positive by mycoplasma-PCR and MG-PCR, respectively. These results indicate the disseminating capacity of this mycoplasma and the possible use of PCR methods for epidemiological analyses and control of farm decontamination before the introduction of new birds.

https://www.tandfonline.com/doi/pdf/10.1080/03079450120118658

Polymerase chain reaction for detection of Mycoplasma gallisepticum in environmental samples.

ErratumErratum to “Detection of Mycoplasma synoviae in poultry environment samples by culture and polymerase chain reaction”: [Vet. Microbiol. 73 (2000) 311–318]☆

Corinne Marois

Papers

Detection of Mycoplasma synoviae in poultry environment samples by culture and polymerase chain reaction

Comparison of pulsed-field gel electrophoresis with random amplified polymorphic DNA for typing of Mycoplasma synoviae.

Polymerase chain reaction for detection of Mycoplasma gallisepticum in environmental samples.

ErratumErratum to “Detection of Mycoplasma synoviae in poultry environment samples by culture and polymerase chain reaction”: [Vet. Microbiol. 73 (2000) 311–318]☆