Detection of viable but non-culturable staphylococci in biofilms from central venous catheters negative on standard microbiological assays

Zandri, Giada; Pasquaroli, Sonia; Vignaroli, Carla; Talevi, S.; Manso, Esther; Donelli, Gianfranco; Biavasco, Francesca

doi:10.1111/j.1469-0691.2012.03893.x

Cited by 69 publications

(43 citation statements)

References 18 publications

(41 reference statements)

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“…were identified in all the sampling sessions in which we used genusspecific PCR. This could be attributed to the use of PCR-based assays, whereby the detection of bacteria in a viable but nonculturable state is possible (59). Moreover, genus-specific PCR indicated that the highest amount of samples (48%) tested positive for Yersinia enterocolitica during sampling two, while sampling one yielded the lowest percentage of positive samples (14%).…”

Section: Discussionmentioning

confidence: 99%

Distribution of Indigenous Bacterial Pathogens and Potential Pathogens Associated with Roof-Harvested Rainwater

Dobrowsky

Kwaadsteniet

Cloete

et al. 2014

Appl Environ Microbiol

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The harvesting of rainwater is gaining acceptance among many governmental authorities in countries such as Australia, Germany, and South Africa, among others. However, conflicting reports on the microbial quality of harvested rainwater have been published. To monitor the presence of potential pathogenic bacteria during high-rainfall periods, rainwater from 29 rainwater tanks was sampled on four occasions (during June and August 2012) in a sustainable housing project in Kleinmond, South Africa. This resulted in the collection of 116 harvested rainwater samples in total throughout the sampling period. The identities of the dominant, indigenous, presumptive pathogenic isolates obtained from the rainwater samples throughout the sampling period were confirmed through universal 16S rRNA PCR, and the results revealed that Pseudomonas (19% of samples) was the dominant genus isolated, followed by Aeromonas (16%), Klebsiella (11%), and Enterobacter (9%). PCR assays employing genusspecific primers also confirmed the presence of Aeromonas spp. In addition, on one sampling occasion, Giardia spp. were detected in 25% of the eight tank water samples analyzed. This study highlights the diverse array of pathogenic bacteria that persist in harvested rainwater during high-rainfall periods. The consumption of untreated harvested rainwater could thus pose a potential significant health threat to consumers, especially children and immunocompromised individuals, and it is recommended that harvested rainwater be treated for safe usage as an alternative water source. R ainwater harvesting (RWH) has been described as an alternative improved water source, as this technology could assist in the provision of water directly to households for drinking and domestic purposes (1). Communities are also able to capture and store rainwater for utilization in small-scale productive activities, such as vegetable gardening, which could make a positive contribution toward food security for individuals from lower socioeconomic groups (2). In addition, low economic growth and the effects of climate change have compelled many governments and water authorities worldwide to rely on the process of harvesting rainwater as an alternative source of water (3).A limited number of qualitative studies (4) have been conducted on the usage of rainwater for domestic and potable purposes, and while some studies have determined that harvested rainwater is safe for drinking purposes without prior treatment (5, 6), a few studies have, however, shown that harvested rainwater is, in fact, not suitable for potable purposes (7, 8, 9, 10, 11). As rainwater is collected from roof surfaces, pathogenic organisms that are found in bird feces, insects, mammals, reptiles, and other debris may be flushed into the tanks via the gutters and the tank inlet systems. This phenomenon could pose serious human health risks (12), and between 1978 and 2006, six incidents of disease related to rainwater were reported (10,13,14).Indicator organisms, such as fecal coliforms and Escherichia coli, ...

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Section: Discussionmentioning

confidence: 99%

Distribution of Indigenous Bacterial Pathogens and Potential Pathogens Associated with Roof-Harvested Rainwater

Dobrowsky

Kwaadsteniet

Cloete

et al. 2014

Appl Environ Microbiol

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“…While the authors conclude that VBNC cells lead to a lower activation of macrophages, the CFU counts were only taken up to 9 h post-infection, which may not have been sufficiently long enough for resuscitation inside the host cells. VBNC Staphylococcus aureus and S. epidermidis cells have also been isolated from biofilms inside catheters (Zandri et al, 2012). More specifically, Pasquaroli et al (2013) found that S. aureus entered a VBNC state upon exposure to antibiotics.…”

Section: Significancesmentioning

confidence: 99%

The importance of the viable but non-culturable state in human bacterial pathogens

et al. 2014

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Many bacterial species have been found to exist in a viable but non-culturable (VBNC) state since its discovery in 1982. VBNC cells are characterized by a loss of culturability on routine agar, which impairs their detection by conventional plate count techniques. This leads to an underestimation of total viable cells in environmental or clinical samples, and thus poses a risk to public health. In this review, we present recent findings on the VBNC state of human bacterial pathogens. The characteristics of VBNC cells, including the similarities and differences to viable, culturable cells and dead cells, and different detection methods are discussed. Exposure to various stresses can induce the VBNC state, and VBNC cells may be resuscitated back to culturable cells under suitable stimuli. The conditions that trigger the induction of the VBNC state and resuscitation from it are summarized and the mechanisms underlying these two processes are discussed. Last but not least, the significance of VBNC cells and their potential influence on human health are also reviewed.

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“…Furthermore, it has been reported that vancomycin, quinupristin/dalfopristin and daptomycin can induce a true VBNC state or persistence in S. aureus cells embedded in biofilms (Zandri et al, 2012;Pasquaroli et al, 2013Pasquaroli et al, , 2014.…”

Section: Detection and Diagnosis Of Medical Biofilmsmentioning

confidence: 99%

Healthcare-associated infections, medical devices and biofilms: risk, tolerance and control

Percival

Suleman

Vuotto

et al. 2015

Journal of Medical Microbiology

602

482

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Detection of viable but non-culturable staphylococci in biofilms from central venous catheters negative on standard microbiological assays

Cited by 69 publications

References 18 publications

Distribution of Indigenous Bacterial Pathogens and Potential Pathogens Associated with Roof-Harvested Rainwater

Distribution of Indigenous Bacterial Pathogens and Potential Pathogens Associated with Roof-Harvested Rainwater

The importance of the viable but non-culturable state in human bacterial pathogens

Healthcare-associated infections, medical devices and biofilms: risk, tolerance and control

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