This research worked is based on the isolation and identification of bacteria associated with used toothbrushes. This study covers the total bacteria count, isolation and identification of bacteria. However, it is limited to very few samples and bacterial studies only, because of limited resources.

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  • Background to the Study

Tooth brushingplaysanimportant everyday role for personal oral hygiene and effective plaqueremoval.Itisthemostcommonlyrecommendedandperformed oral hygiene behaviour and is done ubiquitouslyinbothdevelopedand developingworld. The toothbrush is used on a daily basis to clean the oralcavity. A new toothbrush is usually not a favourable habitatfor bacteria and fungi but in some cases, toothbrushes arealready slightly infected before use (Downes et al., 2019). The oral cavity contains a teaming population of differenttypes of microorganisms (Mehta et al., 2017), some of which are transferredtoatoothbrushduringuse.

Toothbrushes areshowntobecontaminatedattheoralcavityenvironmentandfromhands,aerosolsandthestorageenvironments. The typical storage conditions of toothbrushes may act asa reservoir for the re-introduction of potential pathogens tothe oral cavity and for the introduction of other potentialpathogensfromthebathroomenvironment.Thesemicroorganismshavethepotentialtocolonizetheoralcavitydue to the micro-trauma that toothbrushing can cause.Bacteriawhichattachto,accumulateandsurviveontoothbrushes may be transmitted to the individual, causingdisease(Caudry et al., 2015).

Several authors have done works on bacterial and fungalcontaminationofbrushes,withhigherorlowercontamination being associated with numerous interferencesplacedbetweenthebrushandthehandle(Mehta et al., 2017).Toothbrushhasbeencharacterizedasameansofmicrobialtransport,retention and growth and highly contaminated brushes maycause a possible constant re-infection which is a risk factorfor periodontal disease (Goldschmidt et al., 2014). Toothbrushesplayanessentialroleinoralhygieneandaregenerallyfoundincommunityandhospitalsettings.Theyhavebeenreportedtobeheavilycontaminatedwith microorganisms wheninregularuseandmayplay significantroleindiseasetransmission andincreasetheriskof  infection  since  they  serve  as  a  reservoir  for in healthy, oral-diseased and medically-illadults (Glass, 2012). Contaminated toothbrushes have been suggested to play arole in both systemic and localized diseases. The possibilityoftoothbrushesbeingassociatedwiththetransmissionof heartdiseases,arthritis,bacteremiaandstrokehavealsobeenreported(Sammons et al., 2014). The aim of this study was to isolate, characterize andidentifythebacterialcontaminantsonusedmanualtoothbrushesobtainedfromsomestudentsofthe University of Africa, Toru-orua, Bayelsa State, Nigeria.

1.2 Statement of Problem

Recently, the toothbrush has been characterized as a means of microbial transport, retention and growth (Mehta et al., 2017), and highly contaminated brushes may cause a possible constant “reinfection,” which is a risk factor for periodontal disease (Efstratiou et al., 2007) such as bacterial endocarditis, respiratory pneumonia, osteomyelitis in children, preterm low birth weight, and cardiovascular disease (Jørn et al., 2005). This study was carried out to investigate bacterial contamination of used toothbrushes.

1.3 Aims and Objectives of the Study

This study evaluated microbial contamination of toothbrushes used by students.

The objectives of the study is to

  1. To identify bacteria regularly associated with used toothbrushes
  2. To determine the microbial load of used toothbrushes.
  • To make a recommendation on remedial measures.

1.4 Scope and Limitation

This research worked is based on the isolation and identification of bacteria associated with used toothbrushes. This study covers the total bacteria count, isolation and identification of bacteria. However, it is limited to very few samples and bacterial studies only, because of limited resources.

1.5 Significance of the Study

This study will be useful to all users of toothbrushes by creating awareness of the presence of microorganisms in used toothbrushes.  The outcome of this research will guide users on how to avoid contacting micro-organism mostly from used toothbrushes. It is hoped that the resultof this study will educate the public on the need for soundoralhygienethroughadequate careoftheirtoothbrushes.

This study provides practicalguidancewhich aimedatsupportingallhealthprofessionals,teachers, pupils, and all users of toothbrushes.



A total of thirty used toothbrushes obtained fromthirtystudentsof University of Africa, Bayelsa State,Nigeriawere examined bacteriologically. The result showed that allof them were contaminated with bacteria as well as the unusedtoothbrush which served as control.Thecontaminationoftheusedtoothbrushesbybacteria may come from the oral cavity, storage containers,storage environments, the water used for rinsing and theusers. Fiftybacterialisolateswereidentifiedfromtheusedtoothbrushes.ThebacteriawereStreptococcusmutans,Pseudomonasaeruginosa,Staphylococcusaureus,Staphylococcusepidermidis,EscherichiacoliandEnterobacteraerogenes(Table 4.1).

Similarly to organisms isolated from this work, Sammonsetal. (2014)isolatedStaphylococci, andPseudomonas from the toothbrushes they examined. WhileOshoetal. (2013)isolatedEscherichiacoli,Enterobacter,Staphylococcus aureus, andPseudomonasaeruginosafrom toothbrushes afteruse.Inaddition,Malmbergetal. (2014)isolatedStreptococciandStaphylococcusepidermidisfromtoothbrushesafteruse, whileGlass(2014)reportedthattoothbrushesfrombothhealthy patients and patientswith oral disease containedpotentially pathogenic bacteria such as Staphylococcus spp,Escherichiacoli and Pseudomonasspp. Belloetal. (2013)reportedStaphylococcus,Escherichia,andPseudomonasinusedtoothbrusheswhile Contrerasetal. (2010) reported that the most frequent microorganisms found intoothbrushes used by parents and children for one monthwere Enterobacteriaceae and Pseudomonadaceae. Kozai etal. (2019)alsoreportedthatStreptococcusmutansandpathogenic microorganisms can be transferred readily whena toothbrush is used, increasing the risk of dental caries andinfectiousdiseaseswhileNelsonetal. (2019)alsoisolatedStreptococcusmutansfromusedtoothbrushesusingmicrobiologicalidentification.

Staphylococcus aureus was most frequently isolated fromthe used toothbrushes, with a percentage occurrence of 30 %while Enterobacter aerogenes had the lowest percentageoccurrenceof6 %ontheusedtoothbrushesexamined.Sammons et al. (2014) however isolated Staphylococci (48 %) andPseudomonas(16 %)fromusedtoothbrusheswhile (Oshoetal., 2013)isolatedEscherichiacoli(10 %),Enterobacter(10 %),Staphylococcusaureus (20%),Staphylococcussaprophyticus(20 %)andPseudomonasaeruginosa(40 %).Malmbergetal. (2013)isolated Streptococci (50 %) and Staphylococci (86 %) fromused toothbrushes.

Staphylococcus aureus was detected in 30 % of the usedtoothbrushes examined while Enterobacter aerogenes wasisolated from 6 % of the samples studied. Staphylococci arecommonskininhabitants.Theirpresenceontheusedtoothbrushes in high numbers may come from handling andrinsing of the toothbrushes after use. They are known toproducepotenttoxinswhichareinjurioustohealth.Theyare alsocapableofproducingmanyoralinfectiousdiseases (Tong et al.,2015).

Pseudomonasaeruginosaareopportunisticpathogensresponsible for many nosocomial infections. They are alsoubiquitous in nature including water. Their presence in usedtoothbrushes may be attributable to the storage environmentsuchasthebathroom,toiletandwashingsinks,rinsingwaterandtheair.ThebathroomprovidesahumidenvironmentthatencouragesthegrowthofPseudomonasaeruginosa (Abdul-Hassan et al., 1990).

EscherichiacoliandEnterobacteraerogenesarecoliforms and members of the family Enterobacteriaceae.They are also pathogenic to humans in significant numbers.ThepresenceofEscherichiacolionthetoothbrushesexamined was indicative of fecal contamination. The usedtoothbrushesmusthavebeenstoredinunhygienicenvironmentssuchastoiletandbathroomsinks.Thesebacteria may also have entered the toothbrushes through therinsing water (Caudry et al.,1995).

Streptococciareaetiologicalagentsoftoothdecayandareimportant bacteria found on the teeth, buccal cavity andthroat.Streptococcusmutansareknowntocausedentalcaries by metabolizing different carbohydrates on the teeth (Sakamoto et al.,2005).Sincetheyareoforalorigin,theirpresenceonusedtoothbrushes is not surprising. Improper rinsing of the usedtoothbrushesmayhaveaccountedforthegrowthofthebacteriaonthe samples. Differentbrandsoftoothbrushesaremarketedtothepubliceveryyearwithlittleinformationontheircontaminationbybacteriawithuse.Theuseofuncontaminated toothbrushes will assist in the maintenanceofsoundoralhygieneandreducethehealthriskposedbythecontaminatingbacteria to humans (Holt et al., 1994).


It became clear that contamination of toothbrushes occurs often, even in individuals who should know the ideal conditions for the storage of toothbrushes. All the used toothbrushes examined in this study werecontaminatedwithbacteriawhichareknowntocauseserioushealthproblemsinhumans.


Sincetoothbrushesserveasreservoirsformicroorganismsandplayamajorroleindisease transmission and increase in risk of infections, their care should be given adequate attention.It is recommended that adequaterinsingwithsterilewaterandallowingdryinginairbeforestorageinhygienicdrycontainers.Inadditionsharingoftoothbrushesshould be discouraged.