VetBactBlog

Phase contrast photomicrograph of living Borrelia burgdorferi. Image: Karl-Erik Johansson (SLU & SVA) and Marianne Eklund (SVA).

Members of the phylum Spirochaetes (trivial name: spirochetes) have a very special morphology. They are very thin and rather long (about 0.1-0.3 x 10-20 µm) and spiral shaped. However, in the case of members of the genus Borrelia, the spiral is planar and the morphology is referred to as a “planar flat-wave morphology”. All spirochetes have periplasmic flagella (also referred to as endoflagella or axial filaments) which make them very motile. The motility in combination with the shape make it possible for these bacteria to “swim” in higly viscous media, like mucous membranes.

Phase contrast photomicrographs  and improved dark field photomicrographs of living Borrelia burgdorferi have now been included in VetBact. Dark field photomicrographs of living Borrelia anserina (the fowl spirochetosis agent) have also been included in VetBact. The Borrelia anserina strain was obtained from Bilal Aslam (Inst. of Microbiology at the Univ. of Agriculture, Faisalabad, Pakistan).

Gram staining of the Gram positive bacterium Streptococcus agalactiae, strain 09mas018883, at two different magnifications. The length of the scale bar is equivalent to 5 µm.

We have added a new Gram staining image of Streptococcus agalactiae, strain 09mas018883, and we have replaced one Gram staining image of S. uberis, strain VB 004/11, which was of bad quality, with a new one.

Lise-Lotte Fernstöm (BVF, SLU) has prepared the Gram stained bacteria for photography.

Anna Eriksson and Charlotta Fasth are reading agar plates at the Mastitis Laboratory of the Department of Bacteriology (SVA).

Streptococcus agalactiae cause mastitis in cattle and some other ruminants. We have included new colony images of S. agalactiae on VetBact. The bacteria have been cultivated on bovine blood agar,  a SELMA-plate and purple agar (with lactose). We have also included a picture of the result from a CAMP test of S. agalactiae and S. uberis against Staphylococcus aureus.

Anna Eriksson (SVA) has prepared the SELMA plate and Lise-Lotte Fernström (BVF, SLU) the other agar plates and the CAMP test.

Marianne Eklund (Dept. of Bacteriology, National Veterinary Institute, Uppsala) is preparing the spirochete samples and the microscope for photography.

Dark field micrographs of Borrelia burgdorferi and Leptospira interrogans have now been included in VetBact. B. burgdorferi is the etiological agent of Lyme borreliosis (or Lyme disease). Humans, dogs, horses, cattle and cats are at risk of infection.

Certain serovars of Leptospira spp. may cause leptospirosis in humans, cattle, pigs, horses and companion animals.

The information in the bacterial pages of  VetBact about Borrelia spp. and Leptospira spp. has recently been updated.

Gram staining of Pseudomonas aeruginosa. A and B corresponds to different (3 times) magnifications.

We have added a Gram staining picture of Staphylococcus epidermidis and we have replaced old gram staining pictures of  Moraxella bovis, Pasteurella multocida subsp. multocida and Pseudomonas aeruginosa with images of higher quality. New Gram staining images, which are included in VetBact, will be shown at two different magnifications. One magnification will approximately correspond to what you can observe in the microscope and the other magnification (1.5-6 times higer) will hopefully give a more clear impression of  some of the details, although the resolution is not higher.

Ann-Louise Bergefur (SVA) and Lise-Lotte Fernstöm (BVF, SLU) have done the Gram staining for the new images.