In our study, 10 non-commensal pathogenic
bacteria were found in the case group and only four were noticed in the control
group. In future studies, researchers are expected to find the source of these
species in other parts of the body and record those sites as a reservoir for
systemic and oral infections.
Wang et al reported that contamination with H.
pylori increased in the HCV infected cases in comparison with
healthy controls (33). In current
research we had only one H. pylori positive case that were seropositive for HCV and for better diagnosis
more cases must be evaluated
In our study, a significant association also
was noticed between the prevalence of E. coli with gender. E. coli was shown to be more prevalent among females in
comparison to males .To the best of our knowledge this
is the first report of sex differences in oral carriage of E.coli. Komiyama and
coworkers also reported a higher carriers rate
of oral enterococcal burden among
healthy females than males
research, H. pylori was detected in
the saliva samples of 12 disabled males. A significant association was observed
between the presence of H. pylori and
gender.Other researchers reported that H. pylori infection was
more prevalent in adult male than females(28), that these results were in line
finding. Many subjects with periodontal
pockets were demonstrated to hold H. pylori in the oral
cavity even after deracination of the microorganism from the stomach(29). But
other authors have reported that presence of H.
the saliva may not be associated with gastric infection(30,31).
In our study, K. pneumonia was also isolated from the saliva of
physically disabled volunteers .In a
combined oral imprint culture of 56 elderly stroke sufferers in rehabilitation
unit of a general hospital in Hong Kong. A significant correlation was also
noted between presence of K. pneumoniae in the oral
cavity and higher risk of aspiration pneumonia in susceptible cases(27).
Stroke-related difficulty in oral hygiene maintenance and using dentures may be
associated with this pathogen carriage(27).
can influence the bacterial colonization regarding hospitalization, immune
status alteration, inadequate or poor hygiene, salivary flow reduction and jaw
movement during normal chewing that can enhance Enterobacteriaceae colonization
study, reporting a higher frequency of Enterobacteriaceae among
physically disabled people. This pathogen also was detected in mouth rinse
samples of 32% of individual after head
and neck radiotherapy (18). Radiotherapy can alter oral cavity bacterial community and increased more subjects of Gram-negative
Evaluating oral bacteria in leukemic patients, Klebsiella was shown to
be the most isolated kind, followed by Enterobacteriaceae(19). It was reported that gram negative bacilli can be detected in 2.8% of admitted patients in psychiatric nursery
home in Turkey(24) .In
an oncology hospital in Midwest of Brazil, the presence of Enterobacteriaceae was determined
in the oral cavity of the workers characterizing the phenotypic profile of the
species showing that these bacteria were colonized in the oral cavity of 18.7%
of the participants (25).
In our study,
it was found that the saliva culture in 78% of the case group and 7% of the
controls exhibited different non-oral pathogens. These bacteria may be
originated from GI tract, replicated on the dorsum of the tongue, then
contaminated the saliva. It is in line with result of studies that reported the
tongue could be a primary reservoir for non-oral pathogens such as
Enterobacteriaceae and/or Pseudomonadaceae(21,22).
the microbiota at implants and adjacent teeth were assessed 10 years after the
placement of implants revealing that periodontitis related strains were visible
at 6.2-78.4% of the implants (15). A significant higher count of Tannerella
forsythia, Parvimonas micra, Fusobacterium nucleatum/ necrophorum,
and Campylobacter rectus has been noticed in implants in comparison with
teeth(15). Our findings are in line with these results, indicating that changes
in factors influencing general or oral hygiene can increase the risk of
colonization of different species of microbiota .
factors such as dentures or implants were demonstrated to play a role in
harboring pathogens. In one study, S. aureus, S. pneumoniae, Haemophilus
influenza, H. parainfluenza, E. coli, K. pneumonia,
Proteus mirabilis, E. cloacae and P. aeruginosa have been
isolated from dentures and oral mucosal
surfaces of patients suffered from malodor (12).Saliva samples of removable denture
wearers also contaminated by a various types of non- common pathogenic bacteria
comparing to individuals without dentures (13).however in
our study none of individual have denture.
evaluated the oral microflora of different groups such as old age subjects , healthy removable denture users ,
dental implants , cases undergoing head and neck
radiotherapy , leukemic cases
,comatose patients and children with nail biting habits (12-18). However, the prevalence of non-commensal bacteria in disable cases has not
been fully examined .As
the number of studies carried on the salivary microflora of disabled
individuals is usually lower than those performed on dental plaque, there is a
controversy on similarity of microbial flora between these two sets.(20)
In the present
study, the difference in microbial population of saliva in two groups of disabled
and healthy people has been compared. A variety of non-oral pathogens were
isolated from physically disabled
subjects including E. coli, K. pneumoniae, Shigella sp.,
Pasteurella sp., Pseudomonas sp.,Providencia sp., Serratia sp., Cedecea
sp. and E. cloacae. Disabled cases were unable to maintain the
general and oral health completely, so the microflora in this group was
different from the healthy subjects.
During the past
few years, there has been a growing awareness on the need of disabled
population to have a greater access to dental cares; while there have been a
relatively small number of dentists who have been trained to cover the special
needs of this population.
The frequency of the detected bacteria in both groups
is presented in Table 2. In the case group, Sighella sp. (47%), Klebsiella
pneumoniae (42%) and E. coli (18%) were the main isolated strains (p=0.001).
In the control group, only K. pneumoniae (3%), E. cloacae (2%) and
Cedecea sp. (1%) were exhibited. The saliva specimens of 12 cases and
one subject of the control group showed H. pylori infection (p=0.002) (Figure 1). . All cases
with H. pylori infection were male, indicating that the bacteria was
more prevalent among male than females (p=0.002). Two of H. pylori positive
subjects were also infected to HBV and HCV. E. coli was more prevalent
in females than males (p=0.01). However, the statistical analysis did
not show any significant correlation between gender predilection and the presence
of other bacteria in the saliva (Table 3).
The age in case group ranged from 14 to 59
years (mean age: 33.8±9.7 years) and in the control’s from 16 to 52 years (mean
age: 35.9 ±8.6 years). Among case group two were seropositive for HBV and HCV and
one subject gives history of epileptic seizure 9 months ago. Twenty two percent
of cases were negative for infection to aerobic non-commensal pathogenic bacteria, but in 78% of their
samples, bacterial growth of these bacteria were detected. Among control group,
96% were not positive for infection to non-commensal pathogenic bacteria (p