American foulbrood of the honey bee: Occurrence and distribution of different genotypes of Paenibacillus larvae in the administrative district of Arnsberg (North Rhine‐Westphalia)

Abstract

Between March 2003 and October 2004, Paenibacillus larvae, the aetiological agent of American foulbrood disease of the honey bee, was isolated from broodcombs and honey samples of 54 apiaries in the administrative district of Arnsberg (North Rhine-Westphalia, Germany). Genotyping of 176 P. larvae isolates with repetitive element polymerase chain reaction fingerprinting (rep-PCR) using BOX A1R and MBO REP1 primers revealed five different genotypes (AB, Ab, ab, ass, Acapital BE, Cyrillic). In samples of three apiaries, more than one genotype was detected. A combination of two genotypes was isolated from honey samples of the same hive two times (ab/ass and Ab/ab). The five genotypes were not randomly distributed in the district, but revealed a certain geographical clustering. Possible factors with impact on the genotype diversity and the distribution pattern are discussed.

Genetic diversity among isolates of Paenibacillus larvae from Austria

“…pulvifaciens ERIC III and IV. Peters et al (2006) applied the same techniques and protocols as described by Genersch and Otten (2003) for genotyping of 176 isolates originating from broodcombs and honey samples of 54 apiaries in the administrative district of Arnsberg (North Rhine-Westphalia, Germany). The authors detected five different genotypes (AB, Ab, ab, ab and A<).…”

Reclassification, genotypes and virulence ofPaenibacillus larvae, the etiological agent of American foulbrood in honeybees – a review

“…These results indicate that irrespective of the spore concentration the likelihood to detect clinical symptoms is very low for infections caused by genotype AB (ERIC II) because most of the diseased larvae will be removed due to the hygienic behavior of the nurse bees. Nevertheless, the remaining larvae dying from the disease after cell capping are still sufficient to cause colony collapse and a pest-like disease progression as can be deduced from the fact, that this genotype is frequently isolated from AFB outbreaks in Germany, Sweden, and Finland (Genersch and Otten, 2003;Genersch et al, 2006;Peters et al, 2006). In contrast, infections caused by any other BOX/MBO genotype (ERIC I) can be diagnosed on the basis of clinical symptoms at an early stage and, hence, official measures can be taken directly.…”

Paenibacillus larvae and American Foulbrood – long since known and still surprising

“…There are a few studies available from European countries (Genersch and Otten, 2003;Genersch et al, 2006;Peters et al, 2006;Loncaric et al, 2008) showing that ERIC I and ERIC II are frequently isolated from foulbrood diseased colonies at least in Germany, Austria, Sweden, and Finland whereas ERIC III/IV are absent in these countries. From the American continent even less is known on the epidemiology of P. larvae but obviously ERIC I is rather common whereas ERIC II as well as ERIC III/IV could not be identified in field isolates in recent years so far (Alippi et al, 2004;Antunez et al, 2007).…”

“…Therefore, the standard heat treatment in many protocols will favour germination and detection of P. arvae ERIC I and hamper the detection of P. larvae ERIC II. In epidemiological studies these differences in temperature sensitivity will distort the picture and lead to an overrepresentation of ERIC I strains compared to ERIC II strains (Genersch and Otten, 2003;Peters et al, 2006;Loncaric et al, 2008). In AFB diagnosis these differences will again cause problems in identifying ERIC II infected hives making P. larvae ERIC II a pathogen which is rather difficult to diagnose since clinical symptoms might become visible only at late stages of the disease and standard laboratory protocols for the detection of the pathogen in bee and honey samples might yield false negative results (Tab.…”