Broj kolonija - parametar kakvoće vode

Heterotrofne bakterije (UBB) je zajedničko ime za skupinu bakterija prisutnih u vodi, koje u definiranim uvjetima mogu porasti na hranjivom agaru korištenjem jednostavnih metoda kultivacije. Za svoj rast zahtijevaju organski izvor ugljika. Uloga ovog parametra kroz povijest se mijenjala, a danas se dominantno koristi kao pokazatelj efikasnosti dezinfekcije vode i općih higijenskih uvjeta u distribucijskoj mreži. Ne postoji univerzalna metoda za određivanje heterotrofnih bakterija. Potrebno je primijeniti onu metodu koja će dati najviše rezultate. U ovom radu analizirano je prisustvo UBB/22 i UBB/37 u različitim tipovima vode (sirova, prerađena i bazenska) u Primorsko-goranskoj županiji u periodu 1998.-2015. U sirovoj vodi veći je porast kolonija UBB/22, a u prerađenoj UBB/37. Slatkovodni bazeni u odnosu na morske pokazuju veći porast UBB/37. Također, dodatno su provedena usporedna ispitivanja broja kolonija različitim metodama (vrsta medija, temperatura i vrijeme inkubacije) na uzorcima vode za dijalizu i bazenske vode. U morskoj bazenskoj vodi primjena Marine agara (umjesto YEA) daje značajno veće rezultate broja UBB/37. U vodi za potrebe hemodijalize primjenom TGYA/22°C/7d postignute su najviše vrijednosti broja kolonija, što ukazuje da se primjenom HR EN ISO 6222:2000 vrijednosti broja kolonija u rutini podcjenjuju. Obzirom da je riječ o imunokompromitiranoj skupini populacije, ovaj je rezultat od posebne važnosti. Rezultati ispitivanja ukazuju da izbor metode ima značajan učinak na rezultate ispitivanja (kako kvantitativne tako i kvalitativne), te da su usporedivi samo rezultati dobiveni primjenom iste metode.Heterotrophic plate count (HPC) is the common name for a bacterial group present in the water which, under defined conditions, can grow on nutritive agar by using simple cultivation methods. In order to grow, they need a source of organic carbon. Throughout history, the role of this parameter has been changing. Today, it is predominantly used as an indicator of water disinfection efficiency and common hygienic conditions within a water distribution network. There is no universal method for determining the heterotrophic plate count. The method that provides the best results must be applied. This study analyses the presence of HPC/22 and HPC/37 in different types of water (untreated, processed, and pool water) in Primorje-Gorski Kotar County between 1998 and 2015. Untreated water showed the highest growth in HPC/22 colonies, while processed water showed the highest growth in HPC/37 colonies. Freshwater swimming pools showed higher growth of HPC/37 when compared to the pools filled with seawater. Furthermore, additional parallel tests of colony populations were carried out using different methods (media type, temperature, and incubation time) on water samples used for dialysis and swimming pools. In seawater pools, the application of Marine agar (instead YEA) yields significantly higher amounts of HPC/37. In water used for dialysis, the application of TGYA/22°C/7d yielded the largest number of colonies, indicating the underestimation of the number of colonies obtained by application of HR EN ISO 6222:2000. Because this water is used for a group of immunocompromised people, these results are of special importance. The results of this study indicate that the choice of cultivation method has a significant effect on the results of tests (both quantitative and qualitative), and that the only comparable results are those obtained using the same method

Broj kolonija - parametar kakvoće vode

Heterotrofne bakterije (UBB) je zajedničko ime za skupinu bakterija prisutnih u vodi, koje u definiranim uvjetima mogu porasti na hranjivom agaru korištenjem jednostavnih metoda kultivacije. Za svoj rast zahtijevaju organski izvor ugljika. Uloga ovog parametra kroz povijest se mijenjala, a danas se dominantno koristi kao pokazatelj efikasnosti dezinfekcije vode i općih higijenskih uvjeta u distribucijskoj mreži. Ne postoji univerzalna metoda za određivanje heterotrofnih bakterija. Potrebno je primijeniti onu metodu koja će dati najviše rezultate. U ovom radu analizirano je prisustvo UBB/22 i UBB/37 u različitim tipovima vode (sirova, prerađena i bazenska) u Primorsko-goranskoj županiji u periodu 1998.-2015. U sirovoj vodi veći je porast kolonija UBB/22, a u prerađenoj UBB/37. Slatkovodni bazeni u odnosu na morske pokazuju veći porast UBB/37. Također, dodatno su provedena usporedna ispitivanja broja kolonija različitim metodama (vrsta medija, temperatura i vrijeme inkubacije) na uzorcima vode za dijalizu i bazenske vode. U morskoj bazenskoj vodi primjena Marine agara (umjesto YEA) daje značajno veće rezultate broja UBB/37. U vodi za potrebe hemodijalize primjenom TGYA/22°C/7d postignute su najviše vrijednosti broja kolonija, što ukazuje da se primjenom HR EN ISO 6222:2000 vrijednosti broja kolonija u rutini podcjenjuju. Obzirom da je riječ o imunokompromitiranoj skupini populacije, ovaj je rezultat od posebne važnosti. Rezultati ispitivanja ukazuju da izbor metode ima značajan učinak na rezultate ispitivanja (kako kvantitativne tako i kvalitativne), te da su usporedivi samo rezultati dobiveni primjenom iste metode.Heterotrophic plate count (HPC) is the common name for a bacterial group present in the water which, under defined conditions, can grow on nutritive agar by using simple cultivation methods. In order to grow, they need a source of organic carbon. Throughout history, the role of this parameter has been changing. Today, it is predominantly used as an indicator of water disinfection efficiency and common hygienic conditions within a water distribution network. There is no universal method for determining the heterotrophic plate count. The method that provides the best results must be applied. This study analyses the presence of HPC/22 and HPC/37 in different types of water (untreated, processed, and pool water) in Primorje-Gorski Kotar County between 1998 and 2015. Untreated water showed the highest growth in HPC/22 colonies, while processed water showed the highest growth in HPC/37 colonies. Freshwater swimming pools showed higher growth of HPC/37 when compared to the pools filled with seawater. Furthermore, additional parallel tests of colony populations were carried out using different methods (media type, temperature, and incubation time) on water samples used for dialysis and swimming pools. In seawater pools, the application of Marine agar (instead YEA) yields significantly higher amounts of HPC/37. In water used for dialysis, the application of TGYA/22°C/7d yielded the largest number of colonies, indicating the underestimation of the number of colonies obtained by application of HR EN ISO 6222:2000. Because this water is used for a group of immunocompromised people, these results are of special importance. The results of this study indicate that the choice of cultivation method has a significant effect on the results of tests (both quantitative and qualitative), and that the only comparable results are those obtained using the same method

Broj kolonija - parametar kakvoće vode

Heterotrofne bakterije (UBB) je zajedničko ime za skupinu bakterija prisutnih u vodi, koje u definiranim uvjetima mogu porasti na hranjivom agaru korištenjem jednostavnih metoda kultivacije. Za svoj rast zahtijevaju organski izvor ugljika. Uloga ovog parametra kroz povijest se mijenjala, a danas se dominantno koristi kao pokazatelj efikasnosti dezinfekcije vode i općih higijenskih uvjeta u distribucijskoj mreži. Ne postoji univerzalna metoda za određivanje heterotrofnih bakterija. Potrebno je primijeniti onu metodu koja će dati najviše rezultate. U ovom radu analizirano je prisustvo UBB/22 i UBB/37 u različitim tipovima vode (sirova, prerađena i bazenska) u Primorsko-goranskoj županiji u periodu 1998.-2015. U sirovoj vodi veći je porast kolonija UBB/22, a u prerađenoj UBB/37. Slatkovodni bazeni u odnosu na morske pokazuju veći porast UBB/37. Također, dodatno su provedena usporedna ispitivanja broja kolonija različitim metodama (vrsta medija, temperatura i vrijeme inkubacije) na uzorcima vode za dijalizu i bazenske vode. U morskoj bazenskoj vodi primjena Marine agara (umjesto YEA) daje značajno veće rezultate broja UBB/37. U vodi za potrebe hemodijalize primjenom TGYA/22°C/7d postignute su najviše vrijednosti broja kolonija, što ukazuje da se primjenom HR EN ISO 6222:2000 vrijednosti broja kolonija u rutini podcjenjuju. Obzirom da je riječ o imunokompromitiranoj skupini populacije, ovaj je rezultat od posebne važnosti. Rezultati ispitivanja ukazuju da izbor metode ima značajan učinak na rezultate ispitivanja (kako kvantitativne tako i kvalitativne), te da su usporedivi samo rezultati dobiveni primjenom iste metode.Heterotrophic plate count (HPC) is the common name for a bacterial group present in the water which, under defined conditions, can grow on nutritive agar by using simple cultivation methods. In order to grow, they need a source of organic carbon. Throughout history, the role of this parameter has been changing. Today, it is predominantly used as an indicator of water disinfection efficiency and common hygienic conditions within a water distribution network. There is no universal method for determining the heterotrophic plate count. The method that provides the best results must be applied. This study analyses the presence of HPC/22 and HPC/37 in different types of water (untreated, processed, and pool water) in Primorje-Gorski Kotar County between 1998 and 2015. Untreated water showed the highest growth in HPC/22 colonies, while processed water showed the highest growth in HPC/37 colonies. Freshwater swimming pools showed higher growth of HPC/37 when compared to the pools filled with seawater. Furthermore, additional parallel tests of colony populations were carried out using different methods (media type, temperature, and incubation time) on water samples used for dialysis and swimming pools. In seawater pools, the application of Marine agar (instead YEA) yields significantly higher amounts of HPC/37. In water used for dialysis, the application of TGYA/22°C/7d yielded the largest number of colonies, indicating the underestimation of the number of colonies obtained by application of HR EN ISO 6222:2000. Because this water is used for a group of immunocompromised people, these results are of special importance. The results of this study indicate that the choice of cultivation method has a significant effect on the results of tests (both quantitative and qualitative), and that the only comparable results are those obtained using the same method

Is TBX agar a suitable medium for monitoring Escherichia coli in bathing water using the membrane filtration method?

The use of a suitable method for the enumeration of indicator microorganisms is of crucial importance for reliable monitoring and assessment of the quality of bathing waters. Among other characteristics, the method should be selective enough and ensure acceptable relative recovery of target microorganisms. This study presents the basic parameters, relative recovery and categorical performance characteristics of Tryptone Bile X-glucuronide (TBX) agar for Escherichia coli (E. coli) enumeration in bathing water samples using the membrane filtration method. The results of the relative recovery study, in which TBX agar was compared against temperature- modified ISO 9308- 1:2014, showed that in order to achieve a satisfactory relative recovery of E. coli with TBX agar at 44 ± 0.5 °C, the resuscitation period on a non-selective medium (Minerals Modified Glutamate Agar, MMGA) at 36 ± 2 °C is crucial. Incubation on a double-layer MMGA/TBX medium with a 6-h resuscitation period and alternating incubation on single-layer MMGA and TBX agar with a 4-h resuscitation period resulted in acceptable and very similar relative recovery. The achieved performance characteristics of the tested medium, double- layer MMGA/TBX agar, are acceptable. The selectivity was matrix-dependent and was 60.6% for inland and 69.9% for coastal waters. No significant effect of the resuscitation period on selectivity was recorded. Finally, the results showed that when the resuscitation period on a non-selective medium is included, TBX agar is a suitable medium for E. coli enumeration in bathing water samples using the membrane filtration method and that its use, theoretically, would not have negative effects on the assessment of bathing water qualit