• Getting results in Microbiology 
• Clinical Pathology Club to be formed 
• Case Notes : Immunosuppression in an African Grey Parrot 
• Blue Green Algae Poisoning 
• Updates 

....Packing samples 
• Abstract

....Treatment Compliance 
• Stop Press

...Baby Girl 
• Tail End

Help us to help you

Microbiology can be one of the most helpful of investigations when formulating a diagnosis. But if you don’t take the right sample or don’t treat the sample correctly the results can be most misleading.

The microbiology staff are ready and waiting to help you make a diagnosis. So how can you make the best use of their talents? Firstly they have identified some of the most common pitfalls.

The best results are obtained from cultures of specimens that have been taken before any treatment and have reached the laboratory quickly. It is often not practical to sample before treatment, but false negatives can occur where antibiotics have been administered. Beware the owner who uses up old ear drops or tablets. They may be out of date (the medications that is) but they can still prevent us from growing bacteria in the laboratory.

Ears present a common example. An air dried smear of the discharge made from the swab before plunging it into the transport medium can be very informative. For example, at this time of the year the pollen count in ear cytology rises dramatically!

Bacteriology samples should be submitted using swabs in Amies transport medium, preferably including charcoal, which best preserves the micro organisms present. Dry swabs should be used only for Chlamydia investigations. Other conjunctival swabs should be in transport medium because the number of bacteria involved is likely to be low and they need nurturing if we are to recover them.

Faeces samples arrive in all sorts of containers! Pots are ideal, but pots and pots are better as large samples give more representative results! On the other hand we will always do our best with what you can get. We know that not all your patients are elephants. A faeces sample is better than a swab for culture as Campylobacter and anaerobes are better preserved particularly if you fill the pot (leave a little space for expansion) it avoids the pots exploding.

Please be generous with samples for skin screens and dermatophyte investigations. Remember that multiple sites give the best results for skin scrape microscopy and if you want a culture and sensitivity too, try to include a swab in transport medium. Alternatively if you want to make a technician go very red in the face, just submit one dry scab and request a full skin screen! Oh, sellotape, please try to avoid using it for samples sent to the laboratory, we get ourselves all stuck up with it.

Urine can present a problem, boric acid is the best preservative for bacteriology but if your sample is so small that the crystals will not dissolve then a plain tube is probably better. Simultaneous urinalysis and culture is ideal as we can usually see what we are supposed to be growing. It also helps us to decide if any organism recovered may be a contaminant.

Anaerobes can be tricky, especially if samples have been languishing in the post or fridge. Anaerobes are never given less than 48 hours in the incubator so they can delay the reporting of results. Do phone to check on the progress of your sample through the lab. We cannot make the bacteria grow any more quickly but we can give you an idea of what’s "cooking".

As a foot note it is generally better not to put samples for microbiology into a fridge as this can cause stress to the bacteria and can prevent them growing or at least slow them up. Store samples at room temperature.

If you are not sure please ask, we are here to help you.
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Clinical/Pathology Club to be formed

In response to popular demand we will be starting a Clinical Pathology Club in the Autumn. It is hoped that this will be a bi-monthly evening meeting starting at 7.00 for 7.30 pm to be held at the Laboratory.

There will be food available and the format of the evening will be a short presentation on a subject of interest followed by a discussion on an interesting or problematic clinical (pathology) case(s) followed by an open forum.

Practices will be circulated as soon as a starting date has been arranged. In the mean time if you are interested in joining in please contact Geraldine Hale 01253 899215 to ensure you receive personal notification.
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Case Notes

Immunosuppression in an African Grey Parrot

An 8 month old African Grey parrot with respiratory signs, weight loss and faecal soiling around the cloaca was presented for examination. Antibiotic was administered but unfortunately the bird died within 24hrs without any sign of recovery. The carcase was submitted to the laboratory for post-mortem examination.

PM findings were; moderate wasting of the pectoral muscle, an enlarged and friable liver. The lungs were patchy dark red and in the air sacs there was thickening of the walls with the formation of yellow plaques.

Microbiological cultures for bacteria were negative, possibly due to the antibiotic administered immediately prior to death. Cultures for moulds also proved negative.

A PCR for Chlamydia psittaci was negative

Histologically the liver was autolysed and the air sac plaques consisted of fibrinous exudate in which there were cholesterol clefts and large colonies of Gram positive bacteria, with minimal inflammatory cell infiltration.

A sample of liver was examined using DNA probes for Psittacine Beak and Feather Disease Virus (PBFD) with a Positive result.

PBFD virus generally localises in the feather follicles causing feather dyscrasias. In intensively hand reared chicks some young show an immunosuppressive form of the disease without feather lesions. The clinical signs depend on the location of the secondary bacterial or mycotic infection.

PBFD virus infection should be suspected in intensively reared young parrots which are unwell particularly if they have a panleucopaenia.

Birds may be tested for PBFD virus by submitting feather pulp, blood from a clipped nail or from venipuncture. Because of the risk of cross contamination from other birds or from free virus in the environment the safest method of testing is to blood test via venipuncture.
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Ancient Life Forms

Cyanobacteria are among the most ancient life forms. They are widespread in many aquatic environments, particularly in freshwater lakes and reservoirs and many are toxic. The incidence of cyanobacteria poisoning incidents involving humans and animals in the UK is on the increase particularly during the warmer months.

Forty species

The cyanobacteria are a true prokaryotic bacteria. They contain chlorophyll a and phycoblins but not chlorophyll b. There are about 40 species listed as toxic of which about 25 are planktonic (they float in water). They grow best above 10° C which means in the UK they proliferate in the summer and early autumn. Water with a high phosphorus content is most at risk from the effects of algal bloom.

Cyanobacteria Toxins

Most of the ill effects associated with cyanobacteria on animals and man is due to hepatotoxins. These are low molecular weight peptide toxins. One of the most investigated toxins is Microcrystin LR. Acute exposure to microcrystin can cause extensive necrosis of the liver with fatal haemorrhage or functional failure. In experimental animals the onset can be as quick as 10 minutes and death within 3 hours. There are a range of other toxins associated with cyanobacteria. The other most important group are the neurotoxins. Probably the most well known are the aphanotoxins which are responsible for paralytic shell fish poisoning.

Recreational Water Risk

A range of symptoms have been described in humans following contact with contaminated recreational waters. These include itchiness, rash, conjunctivitis, blistering of the mucous membranes, asthma, fever, diarrhoea, vomiting etc. In animals reported cases of toxicity have been associated with contact with the algal bloom blown up onto the shore line. This can be present as wind blown accumulations of dried and drying algae forming into clumps.

Reference: Hunter, PR. Culture (1993) 14 6-8

Case history

Almost 12 months ago this laboratory investigated a case of sudden death in a dog associated with cyanobacteria toxicosis:-
The owner was in the habit of walking the dog along the shore line of a now disused reservoir. On return from such a walk the dog was taken ill with gastrointestinal symptoms and died within a few hours. The history indicated that on the occasion of the walk the shore line was heavily contaminated by dried algae and that the dog had been retrieving sticks with traces of algae on. Subsequent histopathology and toxicology confirmed hepatotoxicity and confirmation of the presence of a microcrystin toxin.

Foot Note

In the UK one of the leading authorities on cyanobacteria toxicosis is Professor A. Codd PhD at the University of Dundee.
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Updates

Packing and things

We have no wish to discourage effective packing of samples BUT PLEASE DO NOT use sellotape. If youfeel you need to please fold over one end so that we can remove it without having the risk of cutting it off.

The sample tubes provided by NWL do not need any additional sealing. Just wrap the tubes in cotton wool or other absorbent material and place in a biohazard bag before packing.
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Abstract

Do owners comply with drug treatment requirements?

In a survey of 95 owners with dogs being treated with oral anti-bacterials as out-patients 56% reported non-compliance with the recommended treatment. Of these 88% reported 80% compliance. Compliance was higher when owners felt that the veterinary surgeon had spent enough time on the consultation. Moreover, compliance was significantly higher for dogs being treated for gastrointestinal infections compared with those being treated for other diseases.

Reference: Grave, K. Tanem, H. Journal of Small Animal Practice (1999) 40, 158-162
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STOP PRESS

Joanne Kenyon our Administration Co-ordinator is pleased to announce the birth of a 6lb 12oz (3.07kg) baby girl arrived on 22nd July, to be named Jennifer Louise. Mother and child doing well.
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Tail End

Dog scratchings anyone

Police in Manila seized 1320 lb of dog meat bound for sale in restaurants. It was packed in ice and was disguised as goat meat.

Dog meat is believed by the Phillipinos to be an aphrodisiac and is a delicacy in speciality shops in Manila, selling at a premium of £1 a lb over already expensive pork.

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