Isolation of Cronobacter sakazakii from different herbal teas

Abstract

Bacground/Aim. Cronobacter sakazakii (C. sakazakii) is an emerging food-borne pathogen that has increasingly raised interest among the whole public community and food industry, especially in the production of powder infant formula. It has been isolated from water, sediment and soil. The question is whether this pathogen can be present in herbal teas. Herbal teas are widely used for great number of health problems, as an additional or sometimes only “medicine” given. The aim of this study was to investigate the presence of C. sakazakii in herbal teas which are traditionally used for all restricted populations, including newborns and immunocompromised infant and adults. Methods. In this study 150 samples of dried herbal teas were tested: Children (Baby) tea (11), Althaea officinalis (7), Sennae folium (4), Mentha piperita (8), Hypericum perforatum (3), Thymus serpyllum (5), Matricaria recutita (6), Fruit tea (18), Black, Green and Rooibos tea (11), Salvia officinalis (9), Arctostaphylos uva ursi (5), Urtica dioica (3), Achillea millefolium (2), Melissa officinalis (4), Cynosbati fructus (3), Flower Herbal tea (3) and 17 different mixtures of tea (48 samples). The presence of C. sakazakii was also investigated in previously positive samples of prepared teas (48 samples) after 2 h, 12 h and 24 h. C. sakazakii was isolated by the use of the official method ISO TS 22964 : 2006 and confirmed with the biochemical test API 20E (Biomerieux-France). Results. The obtained results showed that C. sakazakii was isolated from 48 (32%) samples dried herbal teas. C. sakazakii was not isolated only from 2 (4%) of the 48 tested samples of prepared tea and in 46 (96%) of the samples C. sakazakii remained viable after 2 h, 12 h and 24 h. Conclusion. Herbal teas should be carefully used, especially for infants and immunocompromited people with severe chronic diseases because of the possibility of infection by C. sakazakii. Better control and improve testing as well as new facts about this pathogen are necessarry

Powdered Infant Formula

“…in herbal teas has been reported by a number of researchers (Tamura et al 1995 ;Chap et al 2009 ;Stojanović et al 2011 ). Given the probable plant-based ecosystem for Cronobacter spp.…”

“…is not surprising. The largest study reported, to date, was by Stojanović et al ( 2011 ), who isolated C. sakazakii from 48/150 (32 %) of samples. The organism can also persist in prepared tea at 21 and 37 °C.…”

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“…Infants, elders, pregnant women, and people who have debilitated immune systems are susceptible populations to foodborne diseases [23]. For example, Cronobacter sakazakii is one of life-threatening bacterium for immunocompromised, low weight individuals and premature infants whose age is less than 28 days [3,[24][25][26][27][28][29]. The infection caused by Cronobacter can be serious for older people and for people whose immune systems are weakened by other illnesses or conditions [30].…”

Members of the Cronobacter genus – characteristics and prevalence in food

“…The Cronobacter genus bacteria were also isolated from tea samples [Maćkiw et al 2011, Turcovský et al 2011. The study conducted by Stojanović et al [2011] showed high prevalence (from 11 to 75%) of C. sakazakii in all kinds of herbal teas, including those intended for infants and children (for example tea from Matricaria recutita).…”