Day 2 :
- Veterinary microbiology
Location: Berlin Room
Chair
Sue Hudson Duran
Auburn University, USA
Co-Chair
Mahdi Saeed
Michigan State University, USA
Session Introduction
Juana Liz Vidal Arboleda
University of Antioquia, Colombia
Title: Characterization of the genetic variability of field strains of Brucella canis isolated in Antioquia, Colombia between 2005-2013
Biography:
Juana Liz Vidal Arboleda has completed her undergraduate studies in Microbiology at the University of Antioquia. She has participated as Colciencias Young
Researcher of the project in the Rio Grande II Reservoir. From 2009-20013, she did specialization in Veterinary Clinical Laboratory in the UDCA (University of
Applied and Environmental Sciences), currently pursuing her Master’s degree in Animal Science in University of Antioquia and serves as Microbiologist and
Bioanalyst in the Laboratory of Veterinary Microbiology, Faculty of Agricultural Sciences at the University of Antioquia.
Abstract:
Introduction: Brucella canis, a facultative intracellular pathogen is responsible for canine brucellosis, a zoonotic disease that
affects canines causing abortions and reproductive failures, human infection may cause mild, asymptomatic or serious medical
conditions. Since 2005 the presence of Brucella canis was demonstrated in Antioquia and the circulating strains were identified
as B. canis type-2, besides recognizing in them the operon virB. In order to learn more about the circulating strains the entire
genome of a wild strain of Brucella canis denoted Oliveri was sequenced, which showed insertions and deletions speciesspecific.
Objective: Characterize the genetic variability of field strains of Brucella canis isolated in Antioquia during 2005-2013.
Methods: A set of six pairs of primers that would allow identification of indels identified in the strain of B. canis str. Oliveri was
designed, after this conventional PCR and sequencing of the amplified products was performed on 30 strains of Brucella canis,
Brucella suis 1330 and bv. 1, Brucella melitensis 16M and vaccine strains of Brucella abortus S19 and RB51.
Results: 5 of 30 field strains studied share indels with the sequenced strain, the remaining 25 strains differ in a deletion exclusive
from the Oliveri strain. Inside the deletions a related one with a critical epimerase for the synthesis of carbohydrates from the
surfaces is present, which is related to the rough characteristics of the colonies like those presented by the field strains. A second
deletion is related to N-acetyltransferase, which prevents the action of aminoglycosides, its absence could facilitate the action
of these antibiotics in the bacteria. A third 6 bp deletions in chromosome II, is related to the ABC transporters superfamily,
which perform the transport of nutrients through the membrane and it is corresponded with a unique characteristic of the
species metabolism. A final deletion related to a glutamic acid tranference RNA is the only exclusive in Oliveri strain, this
deletion may result from the adaptation of the bacteria to intracellular lifestyle more secure and stable with a constant supply
of nutrients, additional we could talk about the effect of speciation and host specific adaptation or as in other Brucella species a
possible recombination process. Inside the insertions studied, one related with an anti prophage repressor which interacts with
prophage repressor genes facilitating horizontal gene transfer was presented; a second insertion evaluated as 60 bp is part of a
hypothetical protein with no specific function but that facilitates differentiation of Brucella canis from other species.
Conclusions: The field strains isolated in Antioquia present genotypic variations from the sequenced strain Oliveri, indicating
that this is not the only strain circulating in the region,which would be useful in future studies to
Juana Liz Vidal Arboleda
University of Antioquia, Colombia
Title: Prevalence of mastitis causing bacteria isolated in two diagnostic laboratories in Antioquia (Colombia), between the years 2013 and 2015
Biography:
Juana Vidal has completed her undergraduate studies in Microbiology at the University of Antioquia. She has participated as Colciencias Young Researcher
of the project in the Rio Grande II Reservoir. From 2009-20013, she did specialization in Veterinary Clinical Laboratory in the UDCA (University of Applied and
Environmental Sciences), currently pursuing her Master’s degree in Animal Science in University of Antioquia and serves as Microbiologist and Bioanalyst in the
Laboratory of Veterinary Microbiology, Faculty of Agricultural Sciences at the University of Antioquia.
Abstract:
Bovine mastitis continues to be the most economically important disease in dairy cattle worldwide and is caused by a
broad spectrum of infectious agents. In the last decade, the main bacteria isolated from mastitic cows in Colombia have
been Streptococcus agalactiae and Staphylococcus aureus. The state of Antioquia is one of the regions in Colombia with major
milk production. Almost 10% of the milking cows present subclinical mastitis diagnoses by somatic cell count or at list with
CMT. Therefore, the microbiological culture is an indispensable preventive and control tool, because it helps producers to
take appropriate decisions. This poster used reports from cultures of submitted milk samples to two veterinary diagnostic
laboratories located in Antioquia. Between the years 2013 and 2015, 7780 milk samples were processed for microbiological
culture at the ICMT-Colanta Laboratory and at Laboratory of Microbiology, School of Veterinary Medicine, University of
Antioquia, using a standard protocol. The most commonly isolated bacteria from all samples were coagulase-negative
Staphylococcus (20.7%), followed by S. aureus (17.9%), S. agalactiae (14.3%), S. uberis (9.1%), others Streptococcus (6.7%), S.
dysgalactiae (5.9%) and others bacteria (3.0%). Gram-negative bacilli were found in 10.0% of the samples; whereas no growth
occurred in 12.0% of cultures. In conclusion, the main bacterial genus isolated was Staphylococcus with a percentage of 38.6%.
The pattern of isolation of mastitis causing bacteria in Colombia has changed over last three years with an increase in the
percentage of isolates of CNS and a decrease in isolates of S. agalactiae.
Juana Liz Vidal Arboleda
University of Antioquia, Colombia
Title: Phylogenetic analysis of the Brucella canis str. Oliveri isolated in Antioquia, Colombia
Biography:
Juana Liz Vidal Arboleda has completed her undergraduate studies in Microbiology at the University of Antioquia. She has participated as Colciencias Young Researcher of
the project in the Rio Grande II Reservoir. From 2009-20013, she did specialization in Veterinary Clinical Laboratory in the UDCA (University of Applied and Environmental
Sciences), currently pursuing her Master’s degree in Animal Science in University of Antioquia and serves as Microbiologist and Bioanalyst in the Laboratory of Veterinary
Microbiology, Faculty of Agricultural Sciences at the University of Antioquia.
Abstract:
recognized and exhibit different host preference; comparative analysis of this genus have show a close genetic relationship between
species. To study the evolution of these species have developed multiple phylogenetic analyzes on which consensus has been separated
into a clade B. melitensis and B. abortus, in another clade marine species and one species consisting of B. suis and B. canis, recognizing
Brucella ovis as the ancestral species, suggesting that the initial contact to pigs, goats and cattles occurred from contact with infected
sheep.
Objective: To establish the phylogenetic relationships and the time of divergence of Brucella canis strain Oliveri.
Methods: Concatenated sequences of these genes were used: glK, trpE, cobQ, aroA, dnaK, rpoB, gap, gyrB, Omp2a, Omp2b, Omp25 and
Omp3 in 24 species of Brucella, including Brucella canis str. Oliveri. Using the Mega 6 program phylogenetic analysis was performed
by the method of neighbor joining with the substitution model Tamura-Nei and 10000 Bootstraps repetititons. The molecular clock
hypothesis among Brucella species was tested and the test of relative rates of Tajima between Brucella canis str. Oliveri and Brucella
canis ATCC was performed.
Results: Phylogenetic analysis including O. anthropi as out group indicate that Brucella ovis was the first lineage split is the most
basal species. The clade with greater genetic diversity is formed by B. suis where it will also find strains of B. canis suggesting a
recent divergence. B. abortus and B. melitensis appear as sister species, being each one monophyletic. Aquatic species B. ceti and
B. pinnipedialis are part of the same clade but separate from the terrestrial strain. Within B. canis all strains present a simultaneous
divergence since they split from their common ancestor, corroborating the result of the test of relative rates of Tajima with P=0.31731.
The molecular clock hypothesis is rejected between species indicating that the rate of evolution of all species of Brucella is not the
same.
Conclusions: The strain of Brucella canis str. Oliveri like others canis species diverged from Brucella suis. The Brucella canis species
had a similar rate of evolution and a genetic distance, so is not possible define which diverged first.
Benson C Iweriebor
University of Fort Hare, South Africa
Title: Climate change and tick-borne bacteria (Rickettsia spp., Anaplasma spp., and Ehrlichia spp.) in ticks collected in the Karoo regions of Eastern Cape, South Africa
Biography:
Benson C Iweriebor is working at AIDS Virus Research Laboratory, Department of Microbiology, University of Venda, South Africa. His research interest include AIDS and Microbiology.
Abstract:
Background: There has been a projected global increase in the distribution and prevalence of infectious diseases with climate change
thus suggesting a pending societal crisis. Global warming causes a wide spectrum of consequences on the human health, including
changes in the spread of tick borne pathogens. Ticks generally play an important role in the transmission and ecology of infectious
diseases. Climatic factors (temperature, rainfall and humidity) strongly influenced the ecology, development, behavior and survival
of ticks and the transmission dynamics of the diseases they transmit.
Objective: The objective of this study was to determine the prevalence of tick-borne bacterial pathogens of the genera Rickettsia spp.,
Ehrlichia spp., and Anaplasma spp. among ticks collected from domesticated ruminants in some selected localities in the Eastern Cape
Province of South Africa where there has been a decreased precipitation and slight increase in temperature recently.
Methods: Between February and May, 2016, a total of 1200 ticks were collected from domesticated ruminant heads in some selected
communities’ within the Nkonkonbe and Chris Hanne District Municipalities in the Eastern Cape, South Africa. Ticks were identified
based on morphological criteria. Genetic detection of tick-borne bacteria belonging to Rickettsia, Anaplasma and Ehrlichia genera
was performed by PCRs. Positive amplicons were sequenced and phylogenetically analyzed.
Results: The ticks were identified as belonging to the genera Rhipicephalus (980) and Amblyomma (220) respectively. Genetic
screening for Rickettsia spp., Ehrlichia spp. and Anaplasma spp. revealed the presence of Rickettsia spp. and Ehrlichia spp. respectively
while none was positive for Anaplasma spp. in the tick samples collected. Ticks from cattle were highly infected with Rickettsia spp.
while Ehrlichia spp. was isolated mainly from ticks collected from sheep. No positive result was obtained from ticks collected from
goats.
Conclusion: The observation that these pathogens are present in ticks on animals within homesteads suggests that inhabitants of
these communities could be infected and tourists visiting the areas should be cautious of tick-biting. The findings of this study show
that zoonotic pathogens are present in ticks in the studied localities. This information will be helpful in the epidemiology of tickborne
zoonotic diseases in the country as well as in creating awareness about such diseases in the veterinary, medical and tourism
sectors, as they may be the mostly affected.
M A Abouelkhair
University of Tennessee, USA
Title: SpA(KKAA) as a candidate Staphylococcus pseudintermedius Vaccine
Biography:
Mohamed Adel Salaheldin Abouelkhair has completed his Master’s degree from University of Sadat City, Egypt. He is an Assistant Lecturer in Bacteriology,
Mycology and Immunology Department, University of Sadat City, Egypt. He is currently a graduate PhD student in Comparative and Experimental Medicine
Graduate Program, College of Veterinary Medicine, University of Tennessee, USA.
Abstract:
Staphylococcus pseudintermedius is an important opportunist bacterium that frequently causes diseases in dogs and
occasionally causes zoonotic infections to human beings. It is commonly associated with canine pyoderma and is also
frequently associated with urinary tract, wound and surgical site infections. The development of a staphylococcal vaccine
is a challenging and prior infection with S. pseudintermedius is not associated with protective immunity. The envelope of S.
pseudintermedius is decorated with staphylococcal protein A (SpA), which captures the Fcγ portion of immunoglobulins to
prevent opsonophagocytosis and associates with the Fab portion of V(H)3-type of B cell receptors to trigger B cell superantigen
activity and consequently ablating adaptive immune responses. We show that mutation of Ig-binding domains of SpA with
amino acid substitutions Glutamine (Q) with Lysine (K) and aspartate (D) with Alanine (A) abolished the ability of the
resulting variant SpA(KKAA) to bind Fc gamma or Fab V(H)3 of B cells which may pave the way for the prevention and therapy
of staphylococcal disease in dogs.
Marita Vedovelli Cardozo
Sao Paulo State University , Brazil
Title: Klebsiella pneumoniae and Escherichia coli producing extended spectrum β-lactamase in broilers production chain
Biography:
Marita Vedovelli Cardozo is a Biologist and Master in Microbiology from Universidade Estadual Paulista (UNESP). Presently, she is a Doctoral student at the same
institution and her work is focused in microbiology with an emphasis on food safety, infectious diseases and public health.
Abstract:
The extended spectrum β-lactamases (ESBL) are enzymes that hydrolyze the β-lactam ring of penicillins, cephalosporins
and aztreonam, conferring resistance to these antimicrobials. There are an increasing number of infections caused by
Gram-negative bacteria producing extended spectrum β-lactamases and the emergence of new therapeutic resources does
not follow the evolution of resistance mechanisms, making them a serious public health problem. Brazil is the largest exporter
of chicken means that the presence of ESBL and it becomes also a potential risk in the agribusiness sector. Based on this, the
present study aims to characterize ESBL production in Enterobacteriaceae isolated from broilers production chain, including
animals, food and consumers. Of the 300 samples collected from cloacal swab, chicken meat and human feces, 36 were resistant
to cefotaxime (CTX) in antimicrobial phenotypic screening. After, by microarray molecular detection, it was found positive
isolates to CTX-M gene. Each positive CTX-M sample was subjected to PCR to confirm the presence of CTX-M-1 and
CTX-M-2 genes and the sequencing showed that all positive samples from CTX-M-1 group belonged to CTX-M-15 gene and
all positive samples from CTX-M-2 group belonged to CTX-M-2 gene. Moreover, identification by MALDI-TOF showed that
36 isolates, 15 were classified as Klebsiella pneumoniae and 21 isolates belong to Escherichia coli. These results evidence of the
correlation of resistance genes between animals and humans show the need to reduce the use of antibiotics in the production
of broilers in the country to combat the spread of antibiotic resistance.