Improved detection of acid mine water stressed coliform bacteria on media containing catalase and sodium pyruvate

1990 ◽  
Vol 36 (8) ◽  
pp. 544-550 ◽  
Author(s):  
Joseph P. Calabrese ◽  
Gary K. Bissonnette

Pure culture suspensions of two strains of exponential and stationary phase Escherichia coli exhibited significant reductions in catalase activity following exposure to acid mine water (AMW). The exogenous addition of catalase (500–2000 U) or sodium pyruvate (0.05–5%) to a nonselective recovery medium resulted in enhanced detection (12- to 465-fold) of AMW-stressed E. coli as compared with recovery on the medium lacking these supplements, whereas addition of 3,3′-thiodipropionic acid failed to improve recovery. Additional in vitro experiments utilizing selective M-FC, mT7, and M-Endo media containing 1000 U catalase or 1.0% pyruvate similarly resulted in improved detection of AMW-stressed cells, with the exception of M-Endo containing pyruvate. Appropriately modified media were then used to analyze an AMW-impacted stream by the membrane filtration technique. Addition of catalase, pyruvate, or a combination of both significantly improved recovery of fecal and total coliforms without promoting growth of noncoliforms. Supplementation of plate count agar with pyruvate and (or) catalase enhanced detection of total heterotrophs. These findings suggest that addition of catalase or pyruvate to standard recovery media may improve detection of coliform and total heterotrophic bacteria in AMW-impacted waters. Key words: acid mine water, coliforms, stress.

1997 ◽  
Vol 60 (11) ◽  
pp. 1302-1305 ◽  
Author(s):  
TODD M. SILK ◽  
ELLIOT T. RYSER ◽  
CATHERINE W. DONNELLY

The main objective of this research was to determine the easiest and most reliable media for enumerating coliform bacteria and Escherichia coli levels in apple cider. During the autumn of 1994 a total of 59 apple cider samples were collected directly from 12 cider producers and were assessed for bacterial levels and pH. Plate count agar was used to determine heterotrophic bacteria levels. Coliform levels were determined using three different media: violet red bile agar (VRBA), Petrifilm High Sensitivity Coliform Count Plates (PHSCCP), and Trypticase soy agar with a VRBA overlay (TSA/VRBA) for attempted recovery of coliforms injured by the low pH of the apple cider. Eosin methylene blue agar (EMBA) and Petrifilm E. coli Count Plates were used to screen cider samples for E. coli. Apple cider had an average pH of 3.34 ± 0.08. Heterotrophic bacterial levels ranged from 2.30 to 7.11 log CFU/ml. All cider samples contained coliform bacteria with levels varying greatly; on the different media, we found the following: on VRBA, <1.00 to 4.37 log CFU/ml; on TSA/VRBA, 1.20 to 4.40 log CFU/ml; and on PHSCCP, < 1.00 to 4.56 log CFU/ml. Coliform levels were most easily determined in apple cider by using PHSCCP. However TSA/VRBA proved to be more reliable; coliform detection was significantly (P < 0.05) increased. EMBA was ineffective for screening apple cider for E. coli, with the low pH of the cider producing many false-positive results. E. coli was only recovered by using Petrifilm E. coli Count Plates with one of the 59 samples positive for E. coli (non-O157:H7) at a level of 10 CFU/ml.


1989 ◽  
Vol 19 (3) ◽  
pp. 237-263 ◽  
Author(s):  
Marcia H. Bates ◽  
John N. Veenstra ◽  
John Barber ◽  
Raju Bernard ◽  
Julie Karleskint ◽  
...  

BMC Urology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Florian H. H. Brill ◽  
Julia Hambach ◽  
Christian Utpatel ◽  
Diana C. Mogrovejo ◽  
Henrik Gabriel ◽  
...  

Abstract Background Long-term use of urethral catheters is associated with high risk of urinary tract infection (UTI) and blockage. Microbial biofilms are a common cause of catheter blockage, reducing their lifetime and significantly increasing morbidity of UTIs. A 0.02% polyhexanide irrigation solution developed for routine mechanical rinsing shows potential for bacterial decolonization of urethral catheters and has the potential to reduce or prevent biofilm formation. Methods Using an in vitro assay with standard market-leading types of catheters artificially contaminated with clinically relevant bacteria, assays were carried out to evaluate the biofilm reduction and prevention potential of a 0.02% polyhexanide solution versus no intervention (standard approach) and irrigation with saline solution (NaCl 0.9%). The efficiency of decolonization was measured through microbial plate count and membrane filtration. Results Irrigation using a 0.02% polyhexanide solution is suitable for the decolonization of a variety of transurethral catheters. The effect observed is significant compared to irrigation with 0.9% saline solution (p = 0.002) or no treatment (p = 0.011). No significant difference was found between irrigation with 0.9% saline solution and no treatment (p = 0.74). Conclusions A 0.02% polyhexanide solution is able to reduce bacterial biofilm from catheters artificially contaminated with clinically relevant bacteria in vitro. The data shows a reduction of the viability of thick bacterial biofilms in a variety of commercially available urinary catheters made from silicone, latex-free silicone, hydrogel-coated silicone and PVC. Further research is required to evaluate the long-term tolerability and efficacy of polyhexanide in clinical practice.


2006 ◽  
Vol 70 (22) ◽  
pp. 5469-5487 ◽  
Author(s):  
Kai-Uwe Ulrich ◽  
André Rossberg ◽  
Harald Foerstendorf ◽  
Harald Zänker ◽  
Andreas C. Scheinost

1986 ◽  
Vol 49 (4) ◽  
pp. 272-273 ◽  
Author(s):  
R. L. DAISE ◽  
E. A. ZOTTOLA ◽  
R. J. EPLEY

Retail cuts of beef and hamburger packages from a North Dakota meat processor were examined due to consumer complaints of a strong potato-like or musty odor associated with the meat. Examination for total numbers of aerobic bacteria on plate count agar and for gram-negative psychrotrophic bacteria on crystal violet tetrazolium agar revealed numbers in excess of 108 CFU/g. Numbers of coliform bacteria on violet red bile agar were in excess of 106 CFU/g. Gram-negative rods were isolated and identified. The isolates were characterized by a positive catalase reaction, oxidase production, an oxidative O/F reaction, nonutilization of lactose, liquefication of nutrient gelatin, slight motility, production of acid in litmus milk with decoloration and clotting, nonproduction of indole, and nonreduction of nitrate. The isolate was tentatively identified as a Pseudomonas of undetermined species, probably a variant of either Pseudomonas taetrolens or Pseudomonas perolens.


2014 ◽  
Vol 48 (23) ◽  
pp. 13685-13693 ◽  
Author(s):  
Juraj Majzlan ◽  
Jakub Plášil ◽  
Radek Škoda ◽  
Johannes Gescher ◽  
Felix Kögler ◽  
...  

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