The genome of Paenibacillus alvei

Researchers from Georg-August University Göttingen Germany have completed the genomic sequence of P. alvei isolate DSM 29 (6.83Mb)  This is an aerobic, Gram-positive bacteria that is often associated with Melissococcus plutonius, the bacterial causative agent of European foul brood disease in honey bees.

Paenibacillus alvei are the larger, elongated bacteria.  Melissococcus plutonius bacteria are clustered in the center.  Photo from the USDA/ARS.

Along with P. alvei, a number of other bacteria also seem to associate frequently with M. plutonius infections including Brevibacillus laterosporus and Enterococcus faecalis.  Of note from the genome are a number of chitinase genes (10) and a hyaluronate lyase homolog, each of which may be virulence factors involved in host cell invasion.  Also, a unique antimicrobial gene and several encoded toxin molecules (binary, mosquitocidal, alveolysin, insecticidal toxin complex) were identified.  454 GS-FLX with Titanium XL was used to sequence paired-end and shotgun DNA libraries, assembled to 18x coverage in 25 contigs.  The genome contains approximately 6,605 coding genes.

A link to the paper in the Journal of Bacteriology is here:
P. alvei genome by Djukic, Becker, Poehlein, Voget, and Daniel

American Bee Research Conference 2013

The annual American Bee Research Conference is a honey bee-centric meeting of bee keepers and researchers being held this week in Hershey, Pennsylvania alongside the somewhat more popular North American Beekeeping Conference.  Bee bug topics are on schedule to be presented, and are linked here:

https://docs.google.com/file/d/0B4dGydUTgVgRZVc5S1AzZUVnUTg/edit


Pollen mites

While not of concern to honey bees, pollen mite (Chaetodactyllus) infestations can be of concern to other bee species, particularly blue orchard bees (Osmia lignaria) and other Osmia species (mason bees, Japanese hornfaced bee, etc.) of the family Megachilidae.  The Krombein's hairy-footed mite (Chaetodactyllus krombeini) is a pollen mite native to North America.  Additional species of Chaetodactyllus occur on other parts of the globe, more commonly in humid rather than arid regions.

When they infest brood cells, they will kill and then feed on bee eggs and larvae.  They will also feed on pollen stores, hence the common name.  Reproduction in the cell can produce a shocking mass of mites: 

USDA/ARS image of C. krombeini mites in a blue orchard bee brood cell.

Emerging adult bees from other cells in the nest can become covered with the mites, and give them a lift to new frontiers.  Some mites may also stay behind in the nest and parasitize a new female bee looking into using the abandoned nest.

Here is a link to a good description of the pollen mite, Chaetodactylus krombeini, from the North American Bee Mite Project at the University of Michigan: Species_Accounts/Chaetodactylus_krombeini.htm.  The second image is from the USDA/ARS.

A recent paper "Distribution of Chaetodactyllus krombeini (Acari: Chaetodactylidae) within Osmia cornifrons (Hymenoptera: Megachilidae) nests: implications for population management" by Matthew McKinney and Yong-Lak Park is here:  http://link.springer.com/article/10.1007/s10493-012-9629-7

Abstract

Chaetodactylus krombeini (Baker) (Acari: Chaetodactylidae) is a cleptoparasitic mite that negatively affects propagation of Osmia spp. (Hymenoptera: Megachilidae) for orchard pollination in the USA. This study was conducted to determine the effect of C. krombeini on mortality of male and female Osmia cornifrons, the Japanese hornfaced bee. A total of 107 O. cornifrons nests were examined to determine within-nest distribution of C. krombeini with regression analyses. A total of 30 mite-free O. cornifrons nests were observed and within-nest distribution of male and female O. cornifrons was determined with non-linear regression analyses. In addition, cocoons from 20 mite-infested O. cornifrons cells were examined to determine whether C. krombeini could be found inside cocoons of O. cornifrons. The results of this study showed that female O. cornifrons and C. krombeini were found more frequently in the inner part of the nest, and male O. cornifrons were found mostly in the center of the nest. No C. krombeini were found inside O. cornifrons cocoons. These results indicate that C. krombeini have a greater negative impact on mortality in the egg and larval stages of female O. cornifrons than in male O. cornifrons. Implications for management of C. krombeini and O. cornifrons populations for orchard pollination are discussed in this article.

The spread of antibiotic resistance genes due to pressure asserted by prolific antibiotic exposure in animals, in this case honey bees.

Antibiotics (oxytetracycline in this case) affect not only targeted pathogens like foul brood bacteria (Paenibacillus and Melissococcus) but also non-targeted endosymbiotic gut flora.  The latest from Nancy Moran's lab.  :

Long-Term Exposure to Antibiotics Has Caused Accumulation of Resistance Determinants in the Gut Microbiota of Honeybees

1. Baoyu Tian^a*, 
2. Nibal H. Fadhil^a, 
3. J. Elijah Powell^a, 
4. Waldan K. Kwong^a, and
5. Nancy A. Moran

http://mbio.asm.org/content/3/6/e00377-12

ABSTRACT

Antibiotic treatment can impact nontarget microbes, enriching the pool of resistance genes available to pathogens and altering community profiles of microbes beneficial to hosts. The gut microbiota of adult honeybees, a distinctive community dominated by eight bacterial species, provides an opportunity to examine evolutionary responses to long-term treatment with a single antibiotic. For decades, American beekeepers have routinely treated colonies with oxytetracycline for control of larval pathogens. Using a functional metagenomic screen of bacteria from Maryland bees, we detected a high incidence of tetracycline/oxytetracycline resistance. This resistance is attributable to known resistance loci for which nucleotide sequences and flanking mobility genes were nearly identical to those from human pathogens and from bacteria associated with farm animals. Surveys using diagnostic PCR and sequencing revealed that gut bacteria of honeybees from diverse localities in the United States harbor eight tetracycline resistance loci, including efflux pump genes (tetB, tetC, tetD, tetH,tetL, and tetY) and ribosome protection genes (tetM and tetW), often at high frequencies. Isolates of gut bacteria from Connecticut bees display high levels of tetracycline resistance. Resistance genes were ubiquitous in American samples, though rare in colonies unexposed for 25 years. In contrast, only three resistance loci, at low frequencies, occurred in samples from countries not using antibiotics in beekeeping and samples from wild bumblebees. Thus, long-term antibiotic treatment has caused the bee gut microbiota to accumulate resistance genes, drawn from a widespread pool of highly mobile loci characterized from pathogens and agricultural sites.

IMPORTANCE We found that 50 years of using antibiotics in beekeeping in the United States has resulted in extensive tetracycline resistance in the gut microbiota. These bacteria, which form a distinctive community present in healthy honeybees worldwide, may function in protecting bees from disease and in providing nutrition. In countries that do not use antibiotics in beekeeping, bee gut bacteria contained far fewer resistance genes. The tetracycline resistance that we observed in American samples reflects the capture of mobile resistance genes closely related to those known from human pathogens and agricultural sites. Thus, long-term treatment to control a specific pathogen resulted in the accumulation of a stockpile of resistance capabilities in the microbiota of a healthy gut. This stockpile can, in turn, provide a source of resistance genes for pathogens themselves. The use of novel antibiotics in beekeeping may disrupt bee health, adding to the threats faced by these pollinators.

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