Laboratory testing protocol to identify critical factors in bacterial compliance monitoring

2003 ◽  
Vol 47 (3) ◽  
pp. 131-136
Author(s):  
M. Abbaszadegan ◽  
P. Ghatpande ◽  
J. Brereton ◽  
A. Alum ◽  
R. Narasimhan

This research focused on providing guidelines for water utilities on the collection and handling of routine bacteriological samples and in developing scientifically-based approaches in selecting the most representative sampling locations. A laboratory-scale pilot distribution system was designed comprising two parallel loops, one using unlined cast-iron pipe and one using PVC pipe. Each loop contained six sampling ports, including (1) a distribution main dead end faucet, (2) one long (5.5 m; 18 feet) and (3) one short (0.3 m; 1 foot) household copper service line with threaded hose-bibb taps, (4) one hose-bibb with welded faucet, (5) one dedicated sampling port (modeled after a manufacturer’s specifications) and (6) one laboratory-style (PVC) stop-cock sampling port. Residual chlorine concentrations were maintained at 0, 0.5, 1.5 and 2.0 mg/L stages during the course of the experiment. Bacterial samples were collected from the different sampling ports and assayed by membrane filtration and/or spread plate. Nutrient and R2A agars were used for heterotrophic plate counts (HPC), m-Endo agar for total coliform (TC) counts and Chromocult agar for injured bacterial analyses. Several methods of sample collection were tested using various combinations of flushing and tap disinfection, including “first flush” (no flushing, without tap disinfection), flushing only, tap disinfection only (using alcohol or hypochlorite solution) and flushing coupled with tap disinfection. The results indicated that the bacterial counts in samples drawn from dead ends were not significantly different from counts in samples from the other sample port configurations. First flush samples consistently produced the highest bacterial count results. Bacterial counts in samples from the long household copper service line were typically three orders of magnitude higher than in samples from the other sample ports. Thus, there is evidence that long copper household service connections may be unsuitable sample tap configurations for collecting samples intended to represent microbial quality in the distribution system.

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Difei Lu ◽  
Xiaohui Guo ◽  
Yun Li ◽  
Bo Zheng ◽  
Junqing Zhang

Our study investigated the effectiveness of bacteria-killing nanotechnology Bio-Kil socks on bacterial burden reduction in diabetic patients and healthy individuals. Four strains of S. aureus and four strains of E. coli were cultured and dropped on Bio-Kil socks and control socks for 0 h, 8 h, and 48 h of incubation. Diluted samples were inoculated and bacterial counts were recorded. Additionally, 31 patients with type 2 diabetes and 31 healthy controls were assigned to wear one Bio-Kil sock on one foot and a control sock on the other for four hours, and then they were told to exchange socks from one foot to the other for four hours. The socks were sampled and diluted and then inoculated to record bacterial counts. Bacterial counts were reduced in Bio-Kil socks compared with control socks in all S. aureus strains after 0 h, 8 h, and 48 h of incubation. In E. coli strains, bacterial counts declined in Bio-Kil socks comparing with control socks in most of the experiments with ESBL-negative E. coli and ATCC35218 at 0 h and 48 h of incubation. In all participants, the mean bacterial counts significantly decreased in Bio-Kil socks in comparison with control socks both at 0 h and at 40 h of incubation (p=0.003 at 0 h and p=0.006 at 40 h). Bio-Kil socks from diabetic patients showed significantly lessened bacterial count at 40 h of incubation (p=0.003). In healthy individuals, Bio-Kil socks reflected a significantly smaller mean bacterial count than control socks (p=0.016). Socks using Bio-Kil nanotechnology efficiently reduce bacterial counts in both diabetic patients and healthy individuals and might exert stronger efficacy in Gram-positive bacteria.


Healthcare ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 850
Author(s):  
Rie Osako ◽  
Yuhei Matsuda ◽  
Chieko Itohara ◽  
Yuka Sukegawa-Takahashi ◽  
Shintaro Sukegawa ◽  
...  

In this retrospective observational study, we evaluated the relationship between perioperative oral bacterial counts and postoperative complications in cardiovascular disease (CVD) patients. From April 2012 to December 2018, all patients scheduled for surgery received perioperative oral management (POM) by oral specialists at a single center. Tongue dorsum bacterial counts were measured on the pre-hospitalization day, preoperatively, and postoperatively. Background data were collected retrospectively. Among the 470 consecutive patients, the postoperative complication incidence rate was 10.4% (pericardial fluid storage, n = 21; postoperative pneumonia, n = 13; surgical site infection, n = 9; mediastinitis, n = 2; and seroma, postoperative infective endocarditis, lung torsion, and pericardial effusion, n = 1 each). Oral bacterial counts were significantly higher in the pre-hospitalization than in the pre- and postoperative samples (p < 0.05). Sex, cerebrovascular disease, and operation time differed significantly between complications and no-complications groups (p < 0.05). Multivariate analysis with propensity score adjustment showed a significant association between postoperative oral bacterial count and postoperative complications (odds ratio 1.26; 95% confidence interval, 1.00–1.60; p = 0.05). Since the development of cardiovascular complications is a multifactorial process, the present study cannot show that POM reduces complications but indicates POM may prevent complications in CVD patients.


Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Helbert Eduardo Espitia ◽  
Iván Machón-González ◽  
Hilario López-García ◽  
Guzmán Díaz

Systems of distributed generation have shown to be a remarkable alternative to a rational use of energy. Nevertheless, the proper functioning of them still manifests a range of challenges, including both the adequate energy dispatch depending on the variability of consumption and the interaction between generators. This paper describes the implementation of an adaptive neurofuzzy system for voltage control, regarding the changes observed in the consumption within the distribution system. The proposed design employs two neurofuzzy systems, one for the plant dynamics identification and the other for control purposes. This focus optimizes the controller using the model achieved through the identification of the plant, whose changes are produced by charge variation; consequently, this process is adaptively performed. The results show the performance of the adaptive neurofuzzy system via statistical analysis.


1997 ◽  
Vol 36 (5) ◽  
pp. 317-324 ◽  
Author(s):  
M.J. Rodriguez ◽  
J.R. West ◽  
J. Powell ◽  
J.B. Sérodes

Increasingly, those who work in the field of drinking water have demonstrated an interest in developing models for evolution of water quality from the treatment plant to the consumer's tap. To date, most of the modelling efforts have been focused on residual chlorine as a key parameter of quality within distribution systems. This paper presents the application of a conventional approach, the first order model, and the application of an emergent modelling approach, an artificial neural network (ANN) model, to simulate residual chlorine in a Severn Trent Water Ltd (U.K.) distribution system. The application of the first order model depends on the adequate estimation of the chlorine decay coefficient and the travel time within the system. The success of an ANN model depends on the use of representative data about factors which affect chlorine evolution in the system. Results demonstrate that ANN has a promising capacity for learning the dynamics of chlorine decay. The development of an ANN appears to be justifiable for disinfection control purposes, in cases when parameter estimation within the first order model is imprecise or difficult to obtain.


1983 ◽  
Vol 91 (3) ◽  
pp. 459-466 ◽  
Author(s):  
W. R. Hudson ◽  
T. A. Roberts ◽  
O. P. Whelehan

SUMMARYIn two surveys of three commercial abattoirs a minimal apparatus method for making bacterial counts, the ‘loop-tile’ method, detected the same trends in bacterial numbers on beef carcasses as the ISO reference method applied to the same samples. Both methods showed the carcasses from one abattoir, that with an export licence, to carry consistently higher numbers of bacteria, and one of the four sites sampled on each carcass to be consistently dirtier than the other three.


2012 ◽  
pp. 11-40
Author(s):  
Emanuele Schimmenti ◽  
Elli Vassiliadis ◽  
Antonino Galati

In recent years, the market globalization process has deeply altered the international competitive scene, leading, inevitably, to a revision of companies' strategies and organization structures. It is now widely accepted that Information and Communication Technology (ict) and supply chain logistics management, have an important role in increasing the competitive potential of each company and in the development of entire economic sectors. The importance of these factors for the business strategies of firms, has generated increasing research attention towards the study of their economic and social impact, concerning both the spread of modern information and communication technologies and logistics. This paper mainly proposes, through a direct survey conducted on a group of firms (production and commercial companies), working in the Sicilian fruit and vegetable sector - a strategic sector in the economic and social field for most of the region - to provide empirical evidence regarding the degree of diffusion of ict and its use, as well as on business relationships with the regional distribution logistics system, as they are two of the determinants that can influence companies' competitive potential. Through Multiple Correspondence Analysis (mca) it was possible to filter down the information from the available data and to identify two factors that describe and summarize how the surveyed firms behave. In particular, the analysis highlighted the close connection between the diffusion and use of ict and logistics distribution organization and the firms' physical and economic size. Specifically, the large-size companies, in this case represented by producer organizations and associations, have a medium-high degree of computerization and an efficient logistics organization, which allows them to interface with competitors both in the national and international market. Agricultural cooperatives and individual companies, on the other hand, though having well-developed infrastructure hardware and software, limit their use to basic functions, but above all have greater needs in terms of logistics structures, which are scantly distributed in the region, and this negatively influences the efficiency of fruit and vegetable produce distribution. In this context, the competitive potential of the fruit and vegetable sector, as regards the issues under investigation, is connected, on the one hand, to companies' recognition of the potential offered by ict and efficient logistics and, on the other, to government intervention aimed at overcoming the region's infrastructure limits which are at the heart of inefficiencies in the distribution system.


2001 ◽  
Vol 1 ◽  
pp. 39-43 ◽  
Author(s):  
V. Zitko

Many countries require the presence of free chlorine at about 0.1 mg/l in their drinking water supplies. For various reasons, such as cast-iron pipes or long residence times in the distribution system, free chlorine may decrease below detection limits. In such cases it is important to know whether or not the water was chlorinated or if nonchlorinated water entered the system by accident. Changes in UV spectra of natural organic matter in lakewater were used to assess qualitatively the degree of chlorination in the treatment to produce drinking water. The changes were more obvious in the first derivative spectra. In lakewater, the derivative spectra have a maximum at about 280 nm. This maximum shifts to longer wavelengths by up to 10 nm, decreases, and eventually disappears with an increasing dose of chlorine. The water treatment system was monitored by this technique for over 1 year and changes in the UV spectra of water samples were compared with experimental samples treated with known amounts of chlorine. The changes of the UV spectra with the concentration of added chlorine are presented. On several occasions, water, which received very little or no chlorination, may have entered the drinking water system. The results show that first derivative spectra are potentially a tool to determine, in the absence of residual chlorine, whether or not surface water was chlorinated during the treatment to produce potable water.


1997 ◽  
Vol 60 (12) ◽  
pp. 1502-1508 ◽  
Author(s):  
JOYCE VAN DONKERSGOED ◽  
KLAUS W. F. JERICHO ◽  
HEIDI GROGAN ◽  
BEN THORLAKSON

An assessment was made of the association between tag (mud, bedding, and manure) attached to hides of beef cattle at slaughter and bacterial deposition on carcasses. A total of 624 carcasses from 52 lots of cattle in southern Alberta from January to June 1996 were studied at a high-line-speed abattoir (HLSP) which processed 285 carcasses per h and at a slow-line-speed abattoir (SLSP) which processed 135 carcasses per h. Tag was quantitatively assessed on the belly, legs, and sides of 12 carcasses per lot by the same project worker (lot tag score) and for each incoming lot of cattle by plant personnel (plant lot tag score). Swabs (approximately 10 by 10 cm) were taken from the medial rump and sacrum immediately after hide removal and from the brisket and top of shoulder after carcass splitting. These samples were pooled for each carcass and aerobic mesophilic bacteria, coliforms, and Escherichia coli were enumerated. The lot bacterial count was calculated by averaging the individual bacterial results of the 12 carcasses in a lot. At the HLSP, the lot side scores and the plant lot tag scores were negatively associated (P &lt; 0.05) with the aerobic bacteria, coliforms, and E. coli. Counts were lower when tag was shaven off of the hides or when the line speed was slowed, but the reductions in counts were less than 0.5 log10/cm2. At the SLSP, the lot belly score was negatively associated (P &lt; 0.003) with the aerobic bacterial counts. Neither the lot tag score nor the plant lot tag score were associated (P &gt; 0.05) with the bacterial counts. Surface wetness of the hides was weakly (P &lt; 0.05) associated with coli forms and E. coli counts. This study indicates that there is no consistent association between lot tag scores, plant lot tag scores, and bacterial contamination of carcasses. Changes in bacterial counts when associated with lot tag scores, plant lot tag scores, surface wetness of hides, line speed, or shaving off of tag were generally less than 0.5 log10/cm2. Thus, these variables are individually assessed as control points, but not critical control points of HACCP plans for the prevailing beef slaughter processes (including line speed adjustment at the HLSP) at the two plants studied.


2005 ◽  
Vol 21 (1-2) ◽  
pp. 99-108 ◽  
Author(s):  
M.A. Kenawi

The effect of microwave heating as a thawing method on physical, chemical sensory, and microbiological properties of frozen chicken was investigated in comparison with other thawing methods (at ambient temperature, in refrigerator, and in running tap water). Microwave thawed chicken had the highest taste panel scores and the lowest drip percentage loss compared with the other thawing methods. Thiobarbituric acid value (TBA) remarkably increased the samples thawed at ambient temperature or under running water. The data revealed that the retention of thiamin was the highest in the microwave thawed samples (97.33%), and the lowest in running water thawed samples (66.66%). The total bacterial count in frozen chicken remarkably decreased as a result of microwave thawing treatment while increased in the other treatments.


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