Biochemical characterization of different genotypes of Paenibacillus larvae subsp. larvae, a honey bee bacterial pathogen

Abstract

Paenibacillus larvae subsp. larvae (P. l. larvae) is the aetiological agent of American foulbrood (AFB), the most virulent bacterial disease of honey bee brood worldwide. In many countries AFB is a notifiable disease since it is highly contagious, in most cases incurable and able to kill affected colonies. Genotyping of field isolates of P. l. larvae revealed at least four genotypes (AB, Ab, ab and aB) present in Germany which are genotypically different from the reference strain DSM 7030. Therefore, based on these data, five different genotypes of P. l. larvae are now identified with genotype AB standing out with a characteristic brown-orange and circled two-coloured colony morphology. Analysing the metabolic profiles of three German genotypes (AB, Ab and ab) as well as of the reference strain using the Biolog system, a characteristic biochemical fingerprint could be obtained for each strain. Cluster analysis showed that while genotypes Ab, ab and the reference strain DSM 7030 are rather similar, genotype AB is clearly different from the others. Analysis of all isolates for plasmid DNA revealed two different plasmids present only in isolates belonging to genotype AB. Therefore, genotype AB is remarkable in all aspects analysed so far. Future analysis will show whether or not these differences will expand to differences in virulence.

Biochemical Profile of Paenibacillus larvae Repetitive Element Polymerase Chain Reaction (rep-PCR) Genotypes in Bulgaria

“…It was found that only three substrates were metabolized by 100% of isolates from genotypes AB and ab, namely D-trehalose, N-аcetyl-D-glucosamine and Nacetyl-β-D-mannosamine. In a study of Neuendorf et al [7] regarding the biochemical characterization of German P. larvae genotypes (AB, Ab, ab) using BioLog Gram positive identification test panel, the authors obtained similar results for D-trehalose (92% AB) and N-аcetyl-Dglucosamine. With respect to N-acetyl-β-D-mannosamine the findings were not comparable.…”

“…An association between genotypes Well А4 А8 B3 В5 В6 В7 В8 С1 С2 С3 С9 D2 D5 E3 E9 G2 Distribution of Bulgarian P. larvae genotypes AB/ab into biotypes according to Jelinski [5] ; Biotype I (reduction of nitrate to nitrite -; acid production from mannitol -; acid production from salicin -); Biotype III (reduction of nitrate to nitrite -; acid production from mannitol + ; acid production from salicin -); Biotype IV (reduction of nitrate to nitrite -; acid production from mannitol -; acid production from salicin +); Biotype V (P. larvae NBIMCC 8478, reduction of nitrate to nitrite + ; acid production from mannitol -; acid production from salicin +); Biotype VIII (reduction of nitrate to nitrite -; acid production from mannitol + ; acid production from salicin +); + = positive reaction; -= negative reaction Şekil 1. Bulgaristan P. larvae genotipleri AB/ab'nin Jelinski'nin bildirdiğine yönteme göre [5] biyotiplere dağılımı; Biyotip I (nitratı nitrite indirgeme -; mannitolden asit üretimi -; salisinden asit üretimi -); Biyotip III (nitratı nitrite indirgeme -; mannitolden asit üretimi + ; salisinden asit üretimi -); Biyotip IV (nitratı nitrite indirgeme -; mannitolden asit üretimi -; salisinden asit üretimi +); Biyotip V (P. larvae NBIMCC 8478, nitratı nitrite indirgeme + ; mannitolden asit üretimi -; salisinden asit üretimi +); Biyotip VIII (nitratı nitrite indirgeme -; mannitolden asit üretimi + ; salisinden asit üretimi +); + = pozitif reaksiyon; -= negatif reaksiyon and their biochemical phenotype was found by Neuendorf et al [7] using the BioLog Gram positive panel with 95 carbon sources as mentioned above. Particular metabolic features of Bulgarian AB and ab isolates were also found based on the 71 carbon sources.…”

“…With the development of molecular typing methods different genotypes of P. larvae have been recognized. The most exploited molecular techniques for typing P. larvae were the repetitive element polymerase chain reaction (rep-PCR) [6][7][8][9] and pulse-field gel electrophoresis (PFGE) [10,11] . There is still little information about the link between different genotypes established with rep-PCR and their phenotype [1,7] .…”

Antibacterial activity of bryophyte species against Paenibacillus larvae isolates

“…P. larvae colony morphology on bacteriological agar is described as whitish to grayish, somewhat transparent and slightly glistening; some colonies produce an orange pigment. P. larvae is catalase-negative or weak-delayed positive and it has a typical carbohydrate acidification profile with acid from glucose and trehalose, not from arabinose and xylose (22,23). In this study, we isolated 22 gram-positive bacteria from larva and honey samples collected from Rize Province.…”

Inhibitory action of essential oils against proteases activity of Paenibacillus larvae, the etiological agent of American Foulbrood disease

“…The hives were located in the province of Buenos Aires, Argentina. Isolation and strains identification were conducted using previously described techniques (Alippi, 1991) and confirmed afterwards according to biochemical and physiological tests (Neuendorf et al, 2004). The P. larvae strains were stored at -20°C on MYPGP agar (Mueller-Hinton broth 19.6% w/v, yeast extract 29.4% w/v, glucose 3.9% w/v, sodium pyruvate 1.96% w/v, PO 4 HK 2 5.9% w/v and agar-agar 39.2% w/v), with 20% v/v of glycerol until used.…”