Honey bees in Riyadh and Al Baha shared gut

Honey bees in Riyadh and Al-Baha shared 18.2% gut bacterial isolates in common. The overall complexity of the microbial communities in honey bees in the Riyadh region was lower (36.4%) than that of Al-Baha (45.5%). This difference in the gut microbial communities might be due to difference in the gut physiological conditions, such as pH, etc. (Yoshiyama and Kimura, 2009), the presence of environmental bacteria from nectar and pollen sources (Anderson et al., 2013), the age of the honey bees, and the season or prevailing characteristics of the environments that affect the geographical location (Gilliam, 1997).
The gut microbial Torin 1 manufacturer of A. m. jemenitica in this study was higher than that in previous culture-dependent studies of A. mellifera (Evans and Armstrong, 2006; Gilliam, 1997; Piccini et al., 2004), but was comparable to that of other studies (Wu et al., 2014; Yoshiyama and Kimura, 2009) in which the microbial diversity of A. c. japonica was enumerated by using culture-dependent methods. However, the microbial diversity of bees from both regions was lower than that of previous studies in which culture-independent methods were used for microbial isolation (Ahn et al., 2012; Anderson et al., 2013; Babendreier et al., 2007; Corby-Harris et al., 2014a; Cox-Foster et al., 2007; Engel and Moran, 2013b; Engel et al., 2012; Horton et al., 2015; Martinson et al., 2011; Mohr and Tebbe, 2006; Moran et al., 2012).
Bacterial species of the genus Bifidobacterium were not detected in the alimentary tract of A. m. jemenitica in Riyadh and Al-Baha, in agreement with the results of Babendreier et al. (2007), Disayathanoowat et al. (2012), Evans and Armstrong (2006), Mohr and Tebbe (2006), Saraithong et al. (2015), Tajabadi et al. (2011a), Wu et al. (2014), Yoshiyama and Kimura (2009). However, the non-detection of Bifidobacterium in this study contradicts the results of Ahn et al. (2012), Anderson et al. (2016, 2013), Corby-Harris et al. (2014a), Cox-Foster et al. (2007), Engel and Moran (2013b), Engel et al. (2012), Gilliam (1997), Horton et al. (2015), Jeyaprakash et al. (2003), Ludvigsen et al. (2015), Martinson et al. (2011), Moran et al. (2012), Olofsson and Vásquez (2008), Sabree et al. (2012). The possible reason for non-detection of Bifidobacterium may be its leower abundance (Horton et al., 2015; Kwong and Moran, 2016), as it comprised only 1.6–3.9% of the bacteria in adult A. mellifera and 0.1–0.4% in A. cerana (Ahn et al., 2012).
Lactobacillus Firm-4 and Firm-5 are considered to be core gut bacteria of A. mellifera, and they have been consistently detected irrespective of geography, environment, and subspecies (Martinson et al., 2011). Evans and Armstrong (2006) did not detect these bacteria in A. mellifera larvae by culture-dependent methods. Lactobacillus were also not detected in the gut of A. c. japonica (Wu et al., 2014; Yoshiyama and Kimura, 2009). In the present study, Lactobacillus Firm-4 and Firm-5 were also detected however, L. kunkeei was detected in bees from Riyadh and Al-Baha. These detected strains were phylogenetically close to the 16S sequences detected in previous studies (Anderson et al., 2013; Olofsson and Vásquez, 2008; Vásquez et al., 2012). Olofsson and Vásquez (2008) and Vásquez et al. (2012) detected a L. kunkeei strain Fhon2, which was consistently detected in honeybees and fresh honey samples. Vojvodic et al. (2013) isolated L. kunkeei from the gut of Africanized and European honey bee larvae, even first instar larvae, and observed a greater abundance in managed honey bees compared to the abundance in bees that had access to a pollination environment. Saraithong et al. (2015) observed abundant L. kunkeei in the gut of A. florea larvae. Anderson et al. (2013) found that L. kunkeei was the most frequent bacterium in the gut of honey bees, and was also present in pure honey, floral nectar, and beebread. However, they suggested that the abundance of L. kunkeei was due to culturing bias, as these bacteria were absent or rare in other culture-independent studies (Corby-Harris et al., 2014a; Engel and Moran, 2013b; Engel et al., 2012; Horton et al., 2015; Martinson et al., 2011; Moran et al., 2012; Sabree et al., 2012). The existence of L. kunkeei in the gut of A. m. jemenitica (this study), and larval guts and flower nectar (Vojvodic et al., 2013), honey bees and fresh honey (Olofsson and Vásquez, 2008), and the gut of A. florea larvae (Saraithong et al., 2015) demands further study to clarify the position of L. kunkeei as a core or non-core gut bacterium.