Survival of probiotic adjunct cultures in cheese and challenges in their enumeration using selective media

Specific gene probe detection methods that utilise a non-selective culturing step were tested for the ability to recognise the presence of quiescent enteric bacteria (Escherichia coli and Enterococcus faecalis ) within illuminated freshwater and seawater microcosms. An E. coli specific uidA gene probe and a 23S rRNA oligonucleotide probe for Enterococci were compared with recoveries using membrane filtration and incubation on selective media (mTEC and mE respectively). From these microcosm experiments a greater initial detection (from 4 hours to 1 day) of E. coli and Ent. faecalis using gene probe methods was observed. Additionally, a comparison of E. coli direct viable counts (DVC) in sunlight exposed microcosms with recoveries by selective media and gene probe methods revealed a large number of viable non-culturable cells. This suggests that enumeration of E. coli by a gene probe method is limited by the replication of the bacteria during the initial non-selective enrichment step. The detection of stressed Ent. faecalis by the oligonucleotide gene probe method was significantly greater than recovery on selective mE agar, indicating an Enterococci non-growth phase.

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Microbiological performance and salmonella dynamics in a wastewater depuration pond system of southeastern spain

Water Science & Technology ◽

10.2166/wst.1995.0492 ◽

1995 ◽

Vol 31 (12) ◽

pp. 239-248 ◽

Cited By ~ 5

Author(s):

Ana Emparanza-Knörr ◽

Francisco Torrella

Keyword(s):

Fecal Coliform ◽

No Reduction ◽

Agar Medium ◽

Microbiological Quality ◽

Total Coliform ◽

Fecal Coliforms ◽

Selective Media ◽

E Coli ◽

The Village ◽

Final Effluent

The Salmonella presence and the microbiological quality indicators, total and fecal coliforms and coliphages of E. coli C, have been studied in a overloaded wastewater lagoon system treating urban wastewatrers of the village of Guardamar del Segura (Alicante, Spain). Classical microbiological technology to detect salmonellae was used, including pre-enrichment, enrichment, selective media plating and biochemical and serological confirmation. Water was physicochemically characterized according to COD, SS, temperature, pH and dissolved oxygen. The selective migration step through Rappaport-Vassiliadis semisolid agar medium was essential for the consistent detection of Salmonella in the different lagoon effluents. Total and fecal coliform levels of up to 105-106 MPN/100 ml were detected in the final effluent. High coliphage concentrations of 103-104 pfu/ml were also found in the effluent waters. Salmonella was always detected in 100 ml samples and eventually reached an order of value of 103 MPN/100 ml. Total coliform reduction was higher in the anaerobic ponds whereas fecal coliforms were more efficiently eliminated in the facultative (mostly “anoxic”) lagoons. Coliphage reduction was higher in the facultative lagoons when compared to the anaerobic ponds. On many occasions, no reduction or eventual increment of the concentration of salmonellae was detected in the effluents from the anaerobic ponds compared to concentrations of the patohogen in the influent raw wasterwaters. The possibility exists for a capacity of Salmonella to multiply in the anoxic phase of the wastewater treatment, but the presence of microorganisms in raw sewage waters which could maskSalmonella detection with the enrichment methodology employed cannot be ruled out.

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Influence of local tetracycline on the microbiota of alveolar osteitis in rats

Brazilian Dental Journal ◽

10.1590/s0103-64402008000200006 ◽

2008 ◽

Vol 19 (2) ◽

pp. 119-123 ◽

Cited By ~ 4

Author(s):

Joseane Maria Dias Bosco ◽

Sérgio Ricardo de Oliveira ◽

Álvaro Francisco Bosco ◽

Christiane Marie Schweitzer ◽

Elerson Gaetti Jardim Júnior

Keyword(s):

Aqueous Solution ◽

Wistar Rats ◽

Blood Agar ◽

Selective Media ◽

Sterile Saline ◽

Alveolar Osteitis ◽

Microbial Samples

The aim of the present study was to evaluate the effects of local tetracycline on the occurrence of alveolar osteitis in rats, and on the microbiota associated to this infection. Forty Wistar rats were randomly assigned to 4 groups (n=10): I - the rats had the maxillary right incisor extracted and the alveolar wound did not receive any treatment; II - adrenaline and Ringer-PRAS were introduced into the alveolar wound; III - the alveolar wound was irrigated with sterile saline; and IV - the alveolar wound was irrigated with an aqueous solution of tetracycline. Microbial samples from the alveolar wounds were collected 2 days after surgery and inoculated on blood agar (with and without 8 µg/mL of tetracycline) and other selective media, and were incubated in either aerobiosis or anaerobiosis at 37ºC, for 2 to 14 days. It was verified that tetracycline reduced the occurrence of alveolar osteitis in the rats and caused significant changes in the microbiota of the surgical sites, decreasing the number of anaerobes and increasing the participation of tetracycline-resistant and multi-resistant microorganisms.

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Comparative Studies on Enrichment And Selective Media for Isolation of Salmonellae from Faecal Specimens

Acta Veterinaria Scandinavica ◽

10.1186/bf03548427 ◽

1977 ◽

Vol 18 (3) ◽

pp. 300-307

Author(s):

J. Ä. Robertsson ◽

O. Söderlind

Keyword(s):

Comparative Studies ◽

Selective Media

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Changes in STEC and bacterial communities during enrichment of manufacturing beef in selective and non-selective media

Food Microbiology ◽

10.1016/j.fm.2020.103711 ◽

2021 ◽

Vol 96 ◽

pp. 103711

Author(s):

Sanga Kang ◽

Joshua T. Ravensdale ◽

Ranil Coorey ◽

Gary A. Dykes ◽

Robert S. Barlow

Keyword(s):

Bacterial Communities ◽

Selective Media

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Airborne Dissemination of Bacteria (Enterococci, Staphylococci and Enterobacteriaceae) in a Modern Broiler Farm and Its Environment

Animals ◽

10.3390/ani11061783 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1783

Author(s):

Susana Sanz ◽

Carmen Olarte ◽

Raquel Hidalgo-Sanz ◽

Laura Ruiz-Ripa ◽

Rosa Fernández-Fernández ◽

...

Keyword(s):

Selective Media ◽

E Coli ◽

Predominant Species ◽

Bacterial Dissemination ◽

Low Emission ◽

Broiler Farm ◽

Cardinal Directions ◽

Dna Profiles ◽

Number Of Bacteria

The role of the air as a vehicle of bacteria dissemination in the farming environment has been previously reported, but still scarcely studied. This study investigated the bacteria density/diversity of the inside and outside air and of litter samples at a broiler farm. Samples were collected considering two seasons, three outside air distances (50/100/150 m) and the four cardinal directions. Selective media was used for staphylococci, enterococci, and Enterobacteriaceae recovery. A high number of bacteria was detected in the litter (2.9 × 105–5.8 × 107 cfu/g) and in the inside air (>105 cfu/m3), but a low emission of bacteria was evidenced in the outside air (<6 cfu/m3). Moreover, the bacteria detected in the farm’s outside air decreased the further from the farm the sample was taken. A total of 544 isolates were identified by MALDI-TOF (146 from the litter, 142 from inside air and 256 from outside air). From these, 162 staphylococci (14 species; S. saprophyticus 40.7%), 176 Enterobacteriaceae (4 species; E. coli 66%) and 190 enterococci (4 species; E. hirae 83%) were detected. E. hirae was the predominant species, and identical PFGE clones were detected in inside and outside samples. The detection of identical DNA profiles in E. hirae isolates from inside and outside samples suggests the role of the air in bacterial dissemination from the inside of the broiler farm to the immediate environment.

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Evaluation of Microbial Culture Techniques for the Isolation of Pythium Insidiosum from Equine Tissues

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063870201400403 ◽

2002 ◽

Vol 14 (4) ◽

pp. 288-294 ◽

Cited By ~ 28

Author(s):

Amy M. Grooters ◽

Amy Whittington ◽

Mae K. Lopez ◽

Michelle N. Boroughs ◽

Alma F. Roy

Keyword(s):

Room Temperature ◽

Microbial Culture ◽

Sample Type ◽

Pythium Insidiosum ◽

Selective Media ◽

Culture Techniques ◽

Media Type ◽

Antibiotic Solution ◽

And Storage ◽

Storage Technique

The purpose of this study was to evaluate the effects of sample handling, storage, and culture techniques on the isolation of Pythium insidiosum from infected equine tissues. Tissue and kunker samples obtained immediately posteuthanasia from a horse with subcutaneous pythiosis were used to assess the effects of sample type (kunkers vs. tissues), media type (selective vs. nonselective), storage technique, and storage time on P. insidiosum isolation rate. Overall, isolation rates were higher from fresh kunkers (94.6%) and stored kunkers (76.4%) than from fresh tissues (8.3%) or stored tissues (4.6%). Isolation of P. insidiosum also occurred more often on antibiotic-containing media than on nonselective media for both fresh and stored samples. For samples that were stored for 1–3 days prior to culture, P. insidiosum isolation rates were highest for the following techniques: kunkers stored at room temperature and plated on selective media (100%), kunkers stored at 4 C and then plated on either nonselective (91.7%) or selective (95.8%) media, kunkers stored on cold packs and then plated on either nonselective (93.8%) or selective (100%) media, kunkers stored in ampicillin solution and plated on selective media (100%), and kunkers stored in ampicillin/gentocin solution and plated on selective media (87.5%). For samples stored for 4–5 days, P. insidiosum isolation rates were highest for kunkers stored at 4 C and then plated on either nonselective (81.3%) or selective (87.5%) media, kunkers stored in ampicillin solution and then plated on selective media (87.5%), and kunkers stored in ampicillin/gentocin solution and plated on selective media (87.5%). Results of this study suggest that optimal isolation rates of P. insidiosum from infected equine tissues are achieved by culturing fresh kunkers on selective media. For samples that cannot be processed immediately, acceptable handling techniques include storage at room temperature for up to 3 days, refrigeration for up to 5 days, shipping on cold packs, and storage in antibiotic solution, each combined with subsequent inoculation on selective media.

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