Sources of Klebsiella and Raoultella species on dairy farms: Be careful where you walk

Abstract

Klebsiella spp. are a common cause of mastitis, milk loss, and culling on dairy farms. Control of Klebsiella mastitis is largely based on prevention of exposure of the udder to the pathogen. To identify critical control points for mastitis prevention, potential Klebsiella sources and transmission cycles in the farm environment were investigated, including oro-fecal transmission, transmission via the indoor environment, and transmission via the outdoor environment. A total of 305 samples was collected from 3 dairy farms in upstate New York in the summer of 2007, and included soil, feed crops, feed, water, rumen content, feces, bedding, and manure from alleyways and holding pens. Klebsiella spp. were detected in 100% of rumen samples, 89% of water samples, and approximately 64% of soil, feces, bedding, alleyway, and holding pen samples. Detection of Klebsiella spp. in feed crops and feed was less common. Genotypic identification of species using rpoB sequence data showed that Klebsiella pneumoniae was the most common species in rumen content, feces, and alleyways, whereas Klebsiella oxytoca, Klebsiella variicola, and Raoultella planticola were the most frequent species among isolates from soil and feed crops. Random amplified polymorphic DNA-based strain typing showed heterogeneity of Klebsiella spp. in rumen content and feces, with a median of 4 strains per 5 isolates. Observational and bacteriological data support the existence of an oro-fecal transmission cycle, which is primarily maintained through direct contact with fecal contamination or through ingestion of contaminated drinking water. Fecal shedding of Klebsiella spp. contributes to pathogen loads in the environment, including bedding, alleyways, and holding pens. Hygiene of alleyways and holding pens is an important component of Klebsiella control on dairy farms.

Klebsiella Species Associated with Bovine Mastitis in Newfoundland

“…Finally, partial rpo B gene sequencing revealed the presence of K. variicola from one farm, which could not be discriminated using the two previous methods. Similar results were also observed in previous studies where Klebsiella oxytoca , Klebsiella variicola and Raoultella planticola were isolated from environmental samples associated with CM [19]. Therefore, it is possible that the prevalence of K. variicola associated with CM might be under-reported, as the results suggest that routinely used identification tests are not sensitive enough to discriminate it from K. pneumoniae .…”

“…Of these, RAPD has many advantages as it is fast, relatively inexpensive and technically less demanding as compared to the other methods of analysis and was therefore chosen for the current study. Limited strain clustering was observed between the K. pneumoniae strains subjected to analysis (Figure 1), which has also been reported in previous studies, suggesting an environmental source of the infection [16], [19], [21], with the exception of farm 6, where the two CM cases were associated with the same K. pneumoniae strain (Figure 1). Therefore, it is possible that there was either direct or indirect animal to animal transmission on farm 6 or that a single environmental strain infected the two animals independently.…”

“…Results also showed that both cases from farm 9 were associated with a single strain of K. variicola (Figure 1) as it was the only bacterium cultured from the submitted milk samples (Table S2). The isolation of K. variicola from milk samples from cows with CM has not been reported previously as this organism is normally found in the environment [19]. In addition, K. variicola has also been previously isolated from plants and certain hospital settings [19], [20].…”

Klebsiella pneumoniae as a key trafficker of drug resistance genes from environmental to clinically important bacteria

“…However as an opportunistic pathogen, it is likely that K. pneumoniae is more often a component of the normal animal gut microbiota. In humans the rate of intestinal K. pneumoniae colonisation has been estimated at 6% [50,51], while in dairy cows the rate may be much higher (~44% among herds in New York, USA, [52]). K. pneumoniae has also been cultured from the faeces of other agricultural and domestic animals, from the cloacae of birds, and from fish, shellfish, insects and earthworms [43,49,[53][54][55][56][57].…”

Bio-Based Succinate Production from Arundo donax Hydrolysate with the New Natural Succinic Acid-Producing Strain Basfia succiniciproducens BPP7

“…Bacteria belonging to the genera Proteus spp., Raoultella spp., Citrobacter spp., and Klebsiella spp. were recovered in the ruminal fluid of dairy cattle, rumen samples, and bovine fecal material [30][31][32]; their occurrence in ruminants could be expected because some of these genera, such as Pantoea, Raoultella, and Citrobacter, are reported to be cellulase-producing bacteria [10,33]. Moreover, according to Mao et al [34], in addition to Proteobacteria, Firmicutes is a predominant phylum found in rumen samples of dairy cattle.…”