Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Alejandra Vásquez is active.

Publication


Featured researches published by Alejandra Vásquez.


Journal of Clinical Microbiology | 2002

Vaginal Lactobacillus Flora of Healthy Swedish Women

Alejandra Vásquez; Tell Jakobsson; Siv Ahrné; Urban Forsum; Göran Molin

ABSTRACT Species of the Lactobacillus acidophilus complex are generally considered to constitute most of the vaginal Lactobacillus flora, but the flora varies between studies. However, this may be due to difficulties in identifying the closely related species within the L. acidophilus complex by using traditional methods and to variations in the vaginal status of the participants. Two hundred two isolates from the vaginal fluids of 23 Swedish women without bacterial vaginosis, as defined by the criteria of Nugent et al. (R. P. Nugent, M. A. Krohn, and S. L. Hillier, J. Clin. Microbiol. 29:297-301, 1991), were typed by randomly amplified polymorphic DNA (RAPD) analysis and identified to the species level by temporal temperature gradient gel electrophoresis, multiplex PCR, and 16S ribosomal DNA sequencing. The vaginal flora of most participants was dominated by a single RAPD type, but five of them harbored two RAPD types representing two different species or strains. The most frequently occurring species were Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, and Lactobacillus jensenii. L. iners has not previously been reported as one of the predominant Lactobacillus species in the vagina.


PLOS ONE | 2012

Symbionts as major modulators of insect health: Lactic Acid Bacteria and honeybees

Alejandra Vásquez; Eva Forsgren; Ingemar Fries; Robert J. Paxton; Emilie Flaberg; Laszlo Szekely; Tobias Olofsson

Lactic acid bacteria (LAB) are well recognized beneficial host-associated members of the microbiota of humans and animals. Yet LAB-associations of invertebrates have been poorly characterized and their functions remain obscure. Here we show that honeybees possess an abundant, diverse and ancient LAB microbiota in their honey crop with beneficial effects for bee health, defending them against microbial threats. Our studies of LAB in all extant honeybee species plus related apid bees reveal one of the largest collections of novel species from the genera Lactobacillus and Bifidobacterium ever discovered within a single insect and suggest a long (>80 mya) history of association. Bee associated microbiotas highlight Lactobacillus kunkeei as the dominant LAB member. Those showing potent antimicrobial properties are acquired by callow honey bee workers from nestmates and maintained within the crop in biofilms, though beekeeping management practices can negatively impact this microbiota. Prophylactic practices that enhance LAB, or supplementary feeding of LAB, may serve in integrated approaches to sustainable pollinator service provision. We anticipate this microbiota will become central to studies on honeybee health, including colony collapse disorder, and act as an exemplar case of insect-microbe symbiosis.


Current Microbiology | 2008

Detection and Identification of a Novel Lactic Acid Bacterial Flora Within the Honey Stomach of the Honeybee Apis mellifera.

Tobias Olofsson; Alejandra Vásquez

This investigation concerned the question of whether honeybees collect bacteria that are beneficial for humans from the flowers that contribute to formation of their honey. Bacteria originating from the types of flowers involved, and found in different anatomic parts of the bees, in larvae, and in honey of different types, were sampled during a 2-year period. 16S rRNA sequencing of isolates and clones was employed. A novel bacterial flora composed of lactic acid bacteria (LAB) of the genera Lactobacillus and Bifidobacterium, which originated in the honey stomach of the honeybee, was discovered. It varied with the sources of nectar and the presence of other bacterial genera within the honeybee and ended up eventually in the honey. It appeared that honeybees and the novel LAB flora may have evolved in mutual dependence on one another. It was suggested that honey be considered a fermented food product because of the LAB involved in honey production. The findings are seen as having clear implications for future research in the area, as providing a better understanding the health of honeybees and of their production and storage of honey, and as having clear relevance for future honeybee and human probiotics.


Apidologie | 2010

Novel lactic acid bacteria inhibiting Paenibacillus larvae in honey bee larvae

Eva Forsgren; Tobias Olofsson; Alejandra Vásquez; Ingemar Fries

We evaluated the antagonistic effects of newly identified lactic acid bacteria (LAB) in the genera Lactobacillus and Bifidobacterium, originating from the honey stomach, on the honey bee pathogen, Paenibacillus larvae. We used inhibition assays on agar plates and honey bee larval bioassays to investigate the effects of honey bee LAB on P. larvae growth in vitro and on AFB infection in vivo. The individual LAB phylotypes showed different inhibition properties against P. larvae growth on agar plates, whereas a combination of all eleven LAB phylotypes resulted in a total inhibition (no visible growth) of P. larvae. Adding the LAB mixture to the larval food significantly reduced the number of AFB infected larvae in exposure bioassays. The results demonstrate that honey bee specific LAB possess beneficial properties for honey bee health. Possible benefits to honey bee health by enhancing growth of LAB or by applying LAB to honey bee colonies should be further investigated.ZusammenfassungDie Amerikanische Faulbrut (AFB) ist eine Krankheit, die junge Honigbienenlarven befällt. Sie ist eine der schädlichsten Bienenkrankheiten und hat große ökonomische Bedeutung für die Imkerei weltweit. Der Erreger der AFB ist das sporenbildende Bakterium Paenibacillus larvae, das den Mitteldarm junger Larven durch kontaminiertes Futter befällt. Die Besiedelung des larvalen Mitteldarms stellt einen der Schlüsselfaktoren für die Pathogenese von P. larvae dar und bestimmte Zusammensetzungen der Mikroflora des Darmes könnten das Wachstum des Krankheitserregers unterdrücken. Kürzlich wurden eine neue Flora von Milchsäurebakterien (LAB) der Gattungen Lactobacillus und Bifidobacterium aus dem Honigmagen der Bienen beschrieben. LAB sind zwar bekannt für die Produktion von antimikrobiellen Substanzen, jedoch gibt es Variationen bezüglich der nutzbringenden Eigenschaften zwischen Arten und Gattungen. In dieser Untersuchung wurde der antagonistische Effekt der Honigbienen-LAB auf P. larvae beurteilt. Wir verwendeten Hemmtests auf Agarplatten und Biotests mit Honigbienenlarven, um diese Effekte zu untersuchen. Die individuellen LAB-Phylotypen zeigten unterschiedliche Hemmeigenschaften gegenüber auf Agarplatten wachsenden P. larvae, während eine Kombination aller 11 LAB-Phylotypen sogar eine totale Hemmung (kein sichtbares Wachstum mehr) von P. larvae bewirkte. Eine Zugabe des LAB-Mix zum Larvenfutter reduzierte signifikant die Anzahl an AFB-infizierten Larven im Biotest.Die Ergebnisse zeigen, dass die für Honigbienen spezifischen LAB nutzbringende Eigenschaften für die Bienengesundheit besitzen. Der mögliche Nutzen einer Applikation von LAB in Bienenvölkern sollte untersucht werden.


Apmis | 2005

Bacterial vaginosis - a microbiological and immunological enigma

Urban Forsum; Elisabet Holst; Per-Göran Larsson; Alejandra Vásquez; Tell Jakobsson; Inger Mattsby-Baltzer

The development of bacterial vaginosis (BV) among women of childbearing age and the resulting quantitative and qualitative shift from normally occurring lactobacilli in the vagina to a mixture of mainly anaerobic bacteria is a microbiological and immunological enigma that so far has precluded the formulation of a unifying generally accepted theory on the aetiology and clinical course of BV. This critical review highlights some of the more important aspects of BV research that could help in formulating new basic ideas respecting the biology of BV, not least the importance of the interleukin mediators of local inflammatory responses and the bacterial shift from the normally occurring lactobacilli species: L. crispatus, L. gasseri, L. jensenii, and L. iners to a mixed flora dominated by anaerobic bacteria.


Journal of Apicultural Research | 2009

The lactic acid bacteria involved in the production of bee pollen and bee bread

Alejandra Vásquez; Tobias Olofsson

Summary Recently a large flora of lactic acid bacteria (LAB) was identified in the honey stomach of the honey bee Apis mellifera. In this study, the presence of this flora in bee pollen and bee bread was investigated. Pollen was collected from the legs of honey bees, and both two week old and two month old bee bread were also obtained for the study. Bacterial isolates cultivated from these bee products were identified using 16S rRNA gene analyzes. The majority of the honey stomach LAB flora was recovered in a viable state from both the pollen and the two week old bee bread, but not from the two month old bee bread. It is demonstrated for the first time that bee bread is probably fermented by the honey stomach LAB flora that has been added to the pollen via regurgitated nectar from the honey stomach. This discovery helps to explain how honey bees standardize the production of bee bread and how it is stored. The presence of the honey stomach LAB and its antimicrobial substances in bee bread also suggests a possible role in the defence against honey bee diseases since the bee bread is consumed by both the larvae and the adult bees.


International Journal of Systematic and Evolutionary Microbiology | 2014

Lactobacillus apinorum sp. nov., Lactobacillus mellifer sp. nov., Lactobacillus mellis sp. nov., Lactobacillus melliventris sp. nov., Lactobacillus kimbladii sp. nov., Lactobacillus helsingborgensis sp. nov. and Lactobacillus kullabergensis sp. nov., isolated from the honey stomach of the honeybee Apis mellifera

Tobias Olofsson; Magnus Alsterfjord; Bo Nilson; Èile Butler; Alejandra Vásquez

We previously discovered a symbiotic lactic acid bacterial (LAB) microbiota in the honey stomach of the honeybee Apis mellifera. The microbiota was composed of several phylotypes of Bifidobacterium and Lactobacillus. 16S rRNA gene sequence analyses and phenotypic and genetic characteristics revealed that the phylotypes isolated represent seven novel species. One grouped with Lactobacillus kunkeei and the others belong to the Lactobacillus buchneri and Lactobacillus delbrueckiisubgroups of Lactobacillus. We propose the names Lactobacillus apinorum sp. nov., Lactobacillus mellifer sp. nov., Lactobacillus mellis sp. nov., Lactobacillus melliventris sp. nov., Lactobacillus kimbladii sp. nov., Lactobacillus helsingborgensis sp. nov. and Lactobacillus kullabergensis sp. nov. for these novel species, with the respective type strains being Fhon13NT ( = DSM 26257T = CCUG 63287T), Bin4NT ( = DSM 26254T = CCUG 63291T), Hon2NT ( = DSM 26255T = CCUG 63289T), Hma8NT ( = DSM 26256T = CCUG 63629T), Hma2NT ( = DSM 26263T = CCUG 63633T), Bma5NT ( = DSM 26265T = CCUG 63301T) and Biut2NT ( = DSM 26262T = CCUG 63631T).


Letters in Applied Microbiology | 2001

Temporal temperature gradient gel electrophoresis (TTGE) as a tool for identification of Lactobacillus casei, Lactobacillus paracasei, Lactobacillus zeae and Lactobacillus rhamnosus

Alejandra Vásquez; Siv Ahrné; Bertil Pettersson; Göran Molin

Aims: To develop a tool for rapid and inexpensive identification of the Lactobacillus casei complex.


Apidologie | 2009

A scientific note on the lactic acid bacterial flora in honeybees in the USA - A comparison with bees from Sweden

Alejandra Vásquez; Tobias Olofsson; Diana Sammataro

Recently, it was discovered by Olofsson and Vasquez (2008) that a novel flora composed of lactic acid bacteria (LAB) of the genera Lactobacillus and Bifidobacterium (Fig. 1), exists in the honey stomach of the honeybee Apis mellifera. The ten different flora members varied numerically with the sources of nectar and the presence of other bacterial genera within the honeybee. Closely related phylotypes of some of the lactic acid bacteria have been encountered before in previous work (Scardovi and Trovatelli, 1969; Jeyaprakash et al., 2003; Babendreier et al., 2007) but only in the intestines of honeybees. It appeared that honeybees and the novel LAB flora evolved in mutual dependence on one another, the LAB obtaining a niche in which nutrients were available, the honeybees and their honey in turn being protected by the LAB from harmful microorganisms. In addition, four novel bacterial phylotypes belonging to the family Pasteurellaceae, were discovered (Fig. 1). In other studies, (Jeyaprakash et al., 2003; Babendreier et al., 2007) clones with high sequence similarities have been found (Fig. 1), but again only in the intestines of honeybees. By comparison, honey stomachs of honeybees (Apis mellifera and A. m. scutellata) collected in the USA were sampled. During spring, honeybees were foraging on flowers that were in bloom (see Tab. I)


BMC Microbiology | 2013

Proteins of novel lactic acid bacteria from Apis mellifera mellifera: an insight into the production of known extra-cellular proteins during microbial stress

Èile Butler; Magnus Alsterfjord; Tobias Olofsson; Christofer Karlsson; Johan Malmström; Alejandra Vásquez

BackgroundLactic acid bacteria (LAB) has been considered a beneficial bacterial group, found as part of the microbiota of diverse hosts, including humans and various animals. However, the mechanisms of how hosts and LAB interact are still poorly understood. Previous work demonstrates that 13 species of Lactobacillus and Bifidobacterium from the honey crop in bees function symbiotically with the honeybee. They protect each other, their hosts, and the surrounding environment against severe bee pathogens, bacteria, and yeasts. Therefore, we hypothesized that these LAB under stress, i.e. in their natural niche in the honey crop, are likely to produce bioactive substances with antimicrobial activity.ResultsThe genomic analysis of the LAB demonstrated varying genome sizes ranging from 1.5 to 2.2 mega-base pairs (Mbps) which points out a clear difference within the protein gene content, as well as specialized functions in the honeybee microbiota and their adaptation to their host. We demonstrate a clear variation between the secreted proteins of the symbiotic LAB when subjected to microbial stressors. We have identified that 10 of the 13 LAB produced extra-cellular proteins of known or unknown function in which some are arranged in interesting putative operons that may be involved in antimicrobial action, host interaction, or biofilm formation. The most common known extra-cellular proteins secreted were enzymes, DNA chaperones, S-layer proteins, bacteriocins, and lysozymes. A new bacteriocin may have been identified in one of the LAB symbionts while many proteins with unknown functions were produced which must be investigated further.ConclusionsThe 13 LAB symbionts likely play different roles in their natural environment defending their niche and their host and participating in the honeybee’s food production. These roles are partly played through producing extracellular proteins on exposure to microbial stressors widely found in natural occurring flowers. Many of these secreted proteins may have a putative antimicrobial function. In the future, understanding these processes in this complicated environment may lead to novel applications of honey crop LAB proteins.

Collaboration


Dive into the Alejandra Vásquez's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Eva Forsgren

Swedish University of Agricultural Sciences

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Bertil Pettersson

Royal Institute of Technology

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Christina Lindholm

Kristianstad University College

View shared research outputs
Researchain Logo
Decentralizing Knowledge