A comparison of routine culture with polymerase chain reaction technology for the detection of Mycoplasma species in feline nasal samples

Chronic Rhinitis in the Cat: An Update

The etiology of feline chronic rhinitis is incompletely understood and often is a diagnosis of exclusion. History, clinical signs, and investigations performed to reach this diagnosis are discussed. Several treatment options are provided, although cure of this frustrating disease is rarely achieved.

Polyarthritis in Goat-Kids Caused by Streptococcus Equi Subspecies Zooepidemicus

Infectious arthritides in goats is mainly caused by mycoplasmas and Caprine Arthritis- Encephalitis virus (CAEV). Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is a member of Lancefield group C beta-hemolytic streptococcus that commonly colonizes the mucous membranes of healthy equids which is also capable to induce different pathological conditions in many animal species. In this paper we described a case of polyarthritis in four Alpine goat-kids caused by S. zooepidemicus. Goat-kids originated from a farm where sheep, llamas, shepherd dogs, cows and horses were kept with goats. During the external examination of carcasses, crusts and discrete hyperemia were seen on the earlobes beneath the ear tag, as well as swollen joints. Necropsy findings included severe fibrinous polyarthritis in all four examined kids. Shoulder, knee and hip joints were affected. From all affected joints S. zooepidemicus was isolated. Neither Mycoplasma spp. nor CAEV genome were detected from the affected joints. Most likely the goatkids were infected with S. zooepidemicus through the lesions on earlobes which were made after the tagging. As a possible source of bacteria, we recognized the horses and dogs. Due to the lack of any signs of illness in other animal species on the farm, as well as negative pathomorphological findings in other organs, we assumed that the isolated strain is highly adapted to goat-kids. Our report is the first described case of polyarthritis in goat-kids caused by S. zooepidemicus.

Antimicrobial use Guidelines for Treatment of Respiratory Tract Disease in Dogs and Cats: Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases

Respiratory tract disease can be associated with primary or secondary bacterial infections in dogs and cats and is a common reason for use and potential misuse, improper use, and overuse of antimicrobials. There is a lack of comprehensive treatment guidelines such as those that are available for human medicine. Accordingly, the International Society for Companion Animal Infectious Diseases convened a Working Group of clinical microbiologists, pharmacologists, and internists to share experiences, examine scientific data, review clinical trials, and develop these guidelines to assist veterinarians in making antimicrobial treatment choices for use in the management of bacterial respiratory diseases in dogs and cats.

Prevalence of selected infectious disease agents in stray cats in Catalonia, Spain

Objectives

The objective of the current study was to investigate the prevalence rates of the following infectious agents in 116 stray cats in the Barcelona area of Spain: Anaplasma phagocytophilum, Bartonella species, Borrelia burgdorferi, Chlamydia felis, Dirofilaria immitis, Ehrlichia species, feline calicivirus (FCV), feline herpesvirus-1 (FHV-1), feline leukaemia virus (FeLV), feline immunodeficiency virus (FIV), haemoplasmas, Mycoplasma species and Rickettsia species.

Methods

Serum antibodies were used to estimate the prevalence of exposure to A phagocytophilum, Bartonella species, B burgdorferi, Ehrlichia species and FIV; serum antigens were used to assess for infection by D immitis and FeLV; and molecular assays were used to amplify nucleic acids of Anaplasma species, Bartonella species, C felis, D immitis, Ehrlichia species, FCV, FHV-1, haemoplasmas, Mycoplasma species and Rickettsia species from blood and nasal or oral swabs.

Results

Of the 116 cats, 63 (54.3%) had evidence of infection by Bartonella species, FeLV, FIV or a haemoplasma. Anaplasma species, Ehrlichia species or Rickettsia species DNA was not amplified from these cats. A total of 18/116 cats (15.5%) were positive for FCV RNA (six cats), Mycoplasma species DNA (six cats), FHV-1 DNA (three cats) or C felis DNA (three cats).

Conclusions and relevance

This study documents that shelter cats in Catalonia are exposed to many infectious agents with clinical and zoonotic significance, and that flea control is indicated for cats in the region.

Feline respiratory disease

Practical relevance:

Non-hemotropic Mycoplasma species are frequently implicated in cases of respiratory disease, and also conjunctivitis, in cats.

Clinical challenges:

Mycoplasma species are considered commensal bacteria of the conjunctiva and the upper respiratory tract of cats, and hence their role as a primary pathogen is difficult to determine. These organisms certainly appear to play a significant role as a secondary pathogen in the upper airways, and there is increasing evidence that in some animals they may represent a primary infection. However, mycoplasmas have not been found in the lower airways of clinically healthy cats – suggesting that, when present, they likely represent a pathologic process. Diagnostic challenges exist as well; Mycoplasma species are not typically identified via cytology due to their small size, and culture of these organisms requires special media and handling. Although PCR has improved identification and allowed for speciation, conflicting culture and PCR results can create a dilemma regarding the clinical relevance of infection.

Evidence base:

This article draws on original research and case reports to provide information about the role of Mycoplasma species in thefeline upper and lower respiratory tract, diagnostic methods and associated challenges, and treatment options.

Audience:

The goal is to provide small animal practitioners with a current and organized review of the often-conflicting literature regarding the role of Mycoplasma species in feline respiratory infections.

Detection of feline Mycoplasma species in cats with feline asthma and chronic bronchitis

Little is known about the aetiology of inflammatory lower airway disease in cats. The aim of this study was to investigate the role of Mycoplasma species in cats with feline asthma (FA) and chronic bronchitis (CB). The study population consisted of 17 cats with FA/CB, and 14 sick cats without clinical and historical signs of respiratory disease, which were euthanased for various other reasons. Nasal swabs, nasal lavage and bronchoalveolar lavage fluid (BALF) samples were taken from patients from both groups. Mycoplasma species culture with modified Hayflick agar and Mycoplasma polymerase chain reaction (PCR) were performed on all samples followed by sequencing of all Mycoplasma species-positive samples for differentiation of subspecies. PCR testing detected significantly more Mycoplasma species-positive BALF samples than Mycoplasma culture (P = 0.021). When cats with oropharyngeal contamination were excluded from comparison, the numbers of Mycoplasma species-positive BALF samples in the group with FA/CB (6/17) and the control group (4/9) were not significantly different (P = 0.6924). While all nasal samples of the cats with FA/CB were negative for Mycoplasma organisms, five samples in the control group (P = 0.041) were positive on PCR. Sequencing revealed Mycoplasma felis in all PCR-positive samples. Mycoplasma species can be detected in the lower airways of cats with FA/CB, as well as in the BALF of sick cats without respiratory signs. Further studies are warranted to investigate the possibility that Mycoplasma species represent commensals of the lower respiratory tract of cats.

Mycoplasma species in cats with lower airway disease: improved detection and species identification using a polymerase chain reaction assay

There is some evidence that Mycoplasma species may be associated with lower airway disease in cats. Retrospective and prospective studies were carried out on a total population of 76 cats but failed to identify any cases of Mycoplasma species infection by bacterial culture alone. The overall prevalence of bacterial infection (15.8%) was also lower than that identified in previous studies. When a molecular detection technique, the PCR-DGGE, was employed the prevalence of Mycoplasma species detected was 15.4%, with M felis, M gateae and M feliminutum species identified, although the significance of these Mycoplasma species in feline lower airway disease remains in question. However, the PCR-DGGE technique allowed species identification and indicated the presence of M feliminutum, a species not previously isolated from the lower airways of cats.

Comparison of culture and PCR to detect Mycoplasma agalactiae and Mycoplasma mycoides subsp. capri in ear swabs taken from goats

This study was designed to evaluate the validity of PCR for the direct detection of Mycoplasma (M.) agalactiae and Mycoplasma mycoides subsp. capri (Mmc), as the two species most frequently causing contagious agalactia (CA) in goats. The PCR method was compared with the traditional culture technique to determine which method was most efficient at identifying all auricular carriers present in herds. The samples analyzed were 307 ear swabs taken from goats reared in a CA endemic area. We assessed the validity of each technique to detect each species and agreement between both methods. For each species, the result was taken as true-positive when at least one of the two tests was positive. Of the swabs tested, 246 were scored positive by PCR (235 and 11 for Mmc and M. agalactiae, respectively) and 117 showed a positive culture result (113 for Mmc and 4 for M. agalactiae). 133 of the PCR-positive samples (124 and 9 for Mmc and M. agalactiae, respectively) yielded negative culture results and 4 culture-positive samples tested negative using PCR (2 for each species). Sensitivity and negative predictive values for PCR were 84.62 and 99.32 (for M. agalactiae) and 99.16 and 97.22% (for Mmc) respectively, and for culture were 30.77 and 97.03 (for M. agalactiae) and 47.08 and 36.08% (for Mmc), respectively. PCR proved to be a rapid and sensitive method for the detection of mycoplasmas in the external ear of asymptomatic carriers. Tools such as this are needed to adopt efficient control measures against CA.

Effect of sample collection methodology on nasal culture results in cats

Empiric antibiotic therapy is often employed to treat feline chronic rhinosinusitis (CRS), however, collection of samples for culture should result in improved antibiotic selection and development of less antibacterial resistance. This study evaluated the effect of sampling method on culture results in 44 cats and found that aerobic and anaerobic cultures were positive significantly more often from nasal flush samples than from tissue biopsy samples. Frequency of positive Mycoplasma species culture did not differ between the two sampling methodologies, although results were discordant in eight sample pairs. Mycoplasma species were cultured from flush samples only in three cats and from biopsy samples only in five cats. These results suggest that a nasal flush sample is adequate for determining the presence of bacterial organisms in feline nasal disease, however, failure to culture Mycoplasma species from a nasal flush must be interpreted with caution.

Prevalence of selected infectious organisms and comparison of two anatomic sampling sites in shelter cats with upper respiratory tract disease

In order to describe the isolation rates of potential pathogens and to compare anatomic sampling site suitability, nasal and pharyngeal swabs were taken from cats with acute clinical upper respiratory disease in a humane society. DNA of feline herpesvirus-1 was amplified from 51 of 52 cats sampled, Mycoplasma species were cultured or detected by PCR in samples from 34 of 42 cats sampled for both culture and PCR, and Bordetella bronchiseptica was isolated from three of 59 cats sampled for aerobic culture. A single swab was positive for calicivirus and no swabs were positive for Chlamydophila felis. Mycoplasma, Pasteurella and Moraxella species were all isolated from at least one cat in which no primary pathogen was identified. With the exception of B. bronchiseptica, which was detected in nasal swabs only, recovery rates for all suspect primary pathogens were comparable between sampling sites.

Primary mycoplasma pneumonia associated with reversible respiratory failure in a cat

A young adult cat was evaluated for respiratory failure. Diagnostic testing, including computed tomography and culture, documented a primary Mycoplasma species pneumonia. The cat was treated aggressively with supportive care, including mechanical ventilation and appropriate antibiotics including doxycycline, and made a complete recovery. This is a unique case in respect of the severity of the Mycoplasma species pneumonia as well as the cat's recovery from severe lung injury.

Clinical use of 16S rRNA gene sequencing to identify Mycoplasma felis and M. gateae associated with feline ulcerative keratitis

Routine bacterial cultures of corneal scrapings from seven cats with either ulcerative feline keratitis, keratomalacia, or both yielded colonies which were identified by 16S rRNA gene sequencing as Mycoplasma felis (six cases) and Mycoplasma gateae (one case). Identification of the pathogens allowed the use of less empirical and more organism-specific therapy.