4. Results and discussion
E. coli was the most prevalent bacteria isolated from different water sources 34/75 (45.3%) followed by
Salmonella spp. 21/75 (28.0%). Besides
E. coli was mainly recovered from drinkers filled from surface water followed by drinkers filled from tap water (53.0 and 41.7%, respectively). Meanwhile
Salmonella spp. were mainly recovered from surface water (40.0%), also
P. aeruginosa and
A. hydrophila were mainly obtained from tap water and drinkers filled out from tap water (100.0 and 20.8%, respectively) (
Table 2). High detection rates of the isolated bacteria were found in the drinkers in comparing to the main water rates.
E. coli isolation in the screened water samples was not in consistent to those found by Selim
et al. [
42]
, (8.0%) and Barbosa et al. [
43], (16.5%) also, Momtaz et al. [
44] , who found that only 4 out of 448 water samples (0.89%) were positive for
E. coli. While, our findings for
Salmonellae isolates were not matched to those isolated by Yam et al. [
45], (18.0%), Haley et al. [
46] (79.2%), Adingra et al. [
47] (15.4%), Momtaz et al. ( [
44] (7.58%), Tracogna et al. [
48] (8.8%), Yhils and Bassey [
49] (12.9%) and Abd El-Tawab et al.[
50] (25.0%). Furthermore,
P. aeruginosa was found in 38.9% and
A. hydrophila wasn’t detected in any of the examined water samples as reported by Mohammed [
51].
Although
E. coli is a normal inhabitant of the intestinal tract of bird, man and animals.It must be pointed out that the water that is supplied to the birds should be free from this pathogen which is a requirement for water intended for the birds. Drinkers are considered important foci for the microbiological quality of the water provided to the birds. Open water supplies, such as troughs and bell drinkers, may present high contamination levels of 10
7 and 10
4 per ml for mesophiles and fecal coliforms [
52]. In the closed system (nipple), the quality of the water offered to the birds is better protected and there are no deleterious effects on bird performance compared to the open systems [
53].
The risk of contamination with
Salmonellas was 6 to 7 times higher when the water given to birds was exposed to the environment [
54]. Besides, more water samples were positive to
Salmonellas in a broiler facility when water was provided in troughs and therefore water was considered an important means of re-infection in birds [
55].
Salmonellas were isolated from 21.6% of the broiler farms and from 12.3% of the water samples examined in Canada by Poppe et al. [
56]. The use of open drinkers in the majority of the farms acts as favorable media to contamination and the presence of
Salmonellas in the litter was considered an important contamination route of the water provided to the birds.
Water systems could provide as an important environmental vehicle (reservoir) for pathogenic organisms and serve as a potential source of water contamination, resulting in a possible health risk for man, accompanied with severe gastrointestinal, food-borne infections in addition to, high mortality rate in the immuno-compromised individuals [
57,
58]. The existence of the pathogenic enteric bacteria represents an alarming circumstance for water- and food-borne epidemics in the screened settings. The isolation of those pathogenic bacteria from water with high percentage in poultry farms necessitated the strict application of biosecurity measures inside the farms and using safe and efficient disinfectants to control those pathogens.
Concerning the serological identification of the isolated
Salmonella and
E. coli as investigated in
Table 3, it showed that the most predominant serotype recovered traits of
E. coli was O157 16/34 (47.1%), followed by O
144 8/34 (23.5%). Meanwhile the percentage of serogroups
S. Kentucky was higher than other recovered serogroups 10/21 (47.6%), followed by
S. Typhimurium.
S. Infants 5 and 4/21 (23.8 and 19.0 %, respectively). The obtained results for determining
E. coli O157 was the parallel to those obtained by Momba et al. [
59], Mersha et al. [
60], El-Leithy et al. [
61] and Goma et al. [
62] (25.56, 4.2, 32.0 33.3, respectively).
S. Kentucky was the prominent serotype detected in poultry water sources; this was in accordance to those found by Hassan et al. [
63], and Djeffal et al. [
64].
E. coli O157 is belonged to the Enterohemorrhagic
E. coli (EHEC), that causes hemorrhagic colitis and are often associated with devastating or life-threatening systemic manifestations, the hemolytic uremic syndrome (HUS), results from Shiga toxins (Stxs) produced by the bacteria in the intestine of the diseased man. While the attention devoted to EHEC O157:H7 is justified by the pathogenicity, low infectious dose, and ability of the bacteria to survive in extra-intestinal environments, a number of non-O157:H7 EHEC cause severe human disease and are often implicated in HUS as O26. Also,
S. Kentucky is a common causative agent of gastroenteritis in humans, poultry act as the main reservoir of
S. Kentucky, and also domestic poultry has played an important role in its global spread of this species.
S. Kentucky has been identified as one of the most prominent
Salmonella serovars isolated from broilers causing diarrhea and high mortalities resulting in severe economic losses [
65,
66].Upon the molecular characterizations (
Figure 1) for the screened traits, it was denoted that all the examined isolates revealed their specific genus identification as well as virulence related genus, indicated their severity at the farm or consumer levels.
Biocidal efficacy of tested disinfectants (
Table 4) showed that all of the isolated bacteria exhibited resistance against both concentrations of iodine (0.5 and 1.0%) and only
P. aeruginosa isolates showed moderate sensitivity by 50.0% after 24h of exposure to 1.0% concentration. A similar pattern was exhibited by most of the recovered isolates to H
2O
2 3.0% conc. where all of them showed resistance at variable degree except for
P. aeruginosa was sensitive by 40.0% after 24h contact time, meanwhile both
E. coli and
P. aeruginosa were sensitive to 5.0% concentration of H
2O
2 after 24h of exposure (55.0 and 40.0%, respectively). Concerning Terminator disinfectant S
almonella spp. was resistant to both of its concentration (0.3 and 0.5%) by 80.0 and 70.0%, respectively. Whilst
E. coli,
P. aeruginosa and
A. hydrophila were sensitive to both concentrations (0.3 and 0.5%) variably where
E. coli was sensitive (45.0 and 50.0%, respectively) after 24h,
P. aeruginosa was sensitive by (45.0 and 60.0%, respectively) after 24h and
A. hydrophila showed sensitivity by (50.0 and 60.0%, respectively) a for the same contact time (
Table 4). Our findings were Similar to those obtained by Amini Tapouk et al. [
67] who reported that
E. fecalis showed high sensitivity to 2.0% glutaraldehyde.
Concerning
in-vitro sensitivity of zeolite nanoparticles, zinc oxide nanoparticles and ZnO-Z nanocomposite at different contact time against tested pathogens as shown in
Table 5, it revealed that all of the tested pathogens (
E. coli,
Salmonella spp.,
P. aeroginosa and
A. hudrophila were significantly resistant to zeolite nanoparticles at
p = 0.000 at all contact times, on the other hand they showed less resistant pattern to ZnO nanoparticles particularly with increasing the contact time mainly after 24hr of exposure where
A. hydrophila,
Salmonella spp.,
P. aeroginosa and
E. coli were sensitive to it as following 48, 43, 42 and 40%, respectively after 24 hr of exposure (at
p= 0.000). Meanwhile ZnO nanocomposite showed a significantly promising results in control of those pathogens where their sensitivity to composite increase with the increase of contact time where
Salmonella spp. was the most affected pathogen (76.0%), followed by
E. coli (73.0%) then
P. aeroginosa (69.0%) and finally
A. hydrophila (63.0%) at
p= 0.000 after 24hr of exposure.
In contrast to the finding in this study de Souza et al. [
68] found that
P. aeruginosa was highly resistant to ZnO-Nps, meanwhile
S. aureus and
S. Typhimurium were sensitive. Stankovic et al. [
69] and Talebian et al. [
70] reported that antimicrobial activity of ZnO-NPs is mainly affected by the morphology of particles. On the other hand Wang et al. [
71] had to some extent similar results to our study were ZnO-coated zeolite was significantly effect in controlling
S. aureus compared to ZnO NPs that showed less effect in their control. Also Wakweya and Jifar [
72] reported that ZnO NPs had lesser antibacterial effect on both
E. coli and S.
aureus thanZnO-Z. Incorporation of the matrix of zeolites with metal oxides such ZnO NPs increases the antibacterial properties of composite [
73] which increase the capacity of it to penetrate the bacterial layer and subsequently increasing its biocidel effect.
FTIR of the synthesized materials as showed in
Figure 2, (a) FTIR of ZnO nanoparticles showed a broad absorption peak at 3423 cm-1 may be attributed to the characteristic peak of hydroxyl group (O-H) [
74,
75]. Peak appeared at 1631 cm-1 may be due to the bending of water molecules and the absorption peaks located in the range from 450-600 cm-1 is due to the presence of Zn-O bond [
76,
77,
78]. In
Figure 2 (b) FTIR of zeolite nanoparticles show, the -OH, -Si-O, and Al-O bonds in the prepared zeolite are presumably responsible for the characteristic absorbance at 3448 cm-1, 1639 cm-1, and below 1042 cm-1 to 467cm-1due to symmetric and asymmetric stretching vibration of zeolite [
79]. In
Figure 2 (c) FTIR of Zeolite/ ZnO nanoparticles show peaks of zeolite ZnO nanoparticles are somewhat sharper and stronger than those of pure zeolite or ZnO indicating weaker interactions and ordered arrangements of ZnO molecules in the zeolite. All stretching vibrations associated with the hydroxide fictional group at frequencies over 3000 cm-1 in the FTIR spectra of zeolite change towards lower frequency, possibly as a result of the chemical bonding activity between Zn+2 and O atoms [
79].
Additionally, the IR spectra of the ZnO-Z nanoparticles showed little variation from the reference material (zeolite) at frequencies below 1640 cm-1, which should be caused by the disordered alignment and irregular conformation of ZnO molecules in the zeolite network [
80]. (Hara et al., 2000). The range between 460 and 530 cm1 is where zinc oxide concentrations peak [
80]. (Hara et al., 2000). We can see that the IR peak of zinc oxide nanoparticles is clearly defined in the FT-IR spectra of the samples containing ZnO nanoparticles and appeared at 441-530 cm-1, also the presence of ZnO nanoparticles in zeolite was confirmed by the interaction between zeolite and ZnO nanoparticles leading to the shift in zeolite peaks like from 1639 cm-1 to 1638 cm-1 and also from 1042 cm-1 to 1030 cm-1.
The current findings of XRD spectrum for the synthesized ZnO NPs, zeolite NPs and ZnO-Z NPs was showed in Figure. 3. The crystalline structure of ZnO NPs
Figure 3(a) was confirmed by the observation of distinct diffraction peaks at 31.7°, 34.4°,36.15°, 47.47°, 56.56°and 62.73° in the spectra which corresponds to the indices of (100), (002), (101), (102), (110) and (103), respectively [
81,
82,
83]. Figure 3 (b) showed XRD of zeolite nanoparticles, the patterns of zeolite peaks were in agreement with (Ref Cod 01-087- 1619) [
84]. (Alswat et al., 2017). While,
Figure 3 (c) showed XRD of ZnO-Z NPs, from which we observed the similar peaks of ZnO NPs were appeared in that composite that showed successful incorporation and preparation of zeolite NPs and ZnO NPs.
Regarding
Figure 5 (a, b), SEM of ZnO nanoparticles showed that the particles were discovered to be less than 100 nm. The particles were discovered to have a large surface area and surface energy, whereby larger-sized particles will aggregate [
85]. The homogenous, smooth, and devoid of any fractures surfaces of the nanoparticles demonstrated proper material production [
86]. While, in the figure 5c, SEM of zeolite nanoparticles have hollow cores and mesoporous shells which offer excellent room for interactions with ZnO nanoparticles. Also,
Figure 5d displayed the SEM pictures that reveal the morphological makeup of the zeolite/ZnO nanoparticles. The morphology of the Zeolite/ZnO nanoparticles showed many pores and voids indicating a larger surface area and porosity. Also small spherical granules of the ZnO nanoparticles injected into the surface of the zeolite are plainly seen.
Shifting to the acute toxicity of zeolite, zinc nanoparticles, and their nanocomposites (
Table 6) in rats was investigated for 10 days following oral administration. Tremors, rapid breathing, an arched back, convulsions, and unconsciousness were toxicity signs that were followed by death. The mortality probability began to rise around 1247, 1805 and 1046 mg/kg b.wt. After oral administration of zeolite, Zinc NPs and their nanocomposites, respectively. The LD
50 was discovered to be 3251, 3709 and 2658 mg/kg respectively, and (LD
100) was reached 8467, 7620 and 6636 mg/kg b.wt., as shown in the
Table 6. These findings showed that zeolites, Zinc NPs and their nanocomposites can be used safely in pharmacological research. For any biological applications or as a therapeutic dose, we used LD50 values of 1/20 for the zeolites, ZnO NPs and their nanocomposites at doses of 162.5, 185.4 and 129.3 mg/kg respectively. Toxicity increased when the medicine dose was increased in the trial, as seen in
Table 7 and
Table 8. For acute oral testing, the maximum dosage (2,000 mg/kg body weight) indicated in OECD Guideline 423 was applied. By oral gavage, a 25.0% aqueous solution of the dosage was given. Prior to dosing, after two hours, on day 1, at least once each day for a total of one week, the animals were monitored for treatment-related effects. All rats underwent gross pathology 10 days following oral treatment. No animals perished while the study was being conducted. One rat showed reductions in body weight and fecal excretion on day 3 of observation, but these findings vanished four days following medication. Two weeks following oral delivery, there were no unusual findings during necropsy. The approximate acute oral toxicity (LD
50) was >2,000 mg/kg b.wt. for male Sprague-Dawley rats.
From these study and through the probit analysis LD50 had been estimated and measured; depends upon the LD50 results; the tested therapeutic doses were determined and calculated for its use in the biomedical applications at this research as 1/20 from the calculated LD50 had been tested as follow;
Zeolite === LD50 = 3251 x 1/20 = 162.50 mg/kg
ZnO NPs==== LD50 = 3709 x 1/20 = 185.45 mg/kg
Nanocomposite ==== LD50 = 2658 x 1/20 = 129.3 mg/kg
That’s indicate the highly significant safety of the tested nanomaterials
From the obtained data its illustrates that ZnO NPs are the most safe prepared materials at this study with median lethal dose equal to 3709 mg/kg b.wt., while 3251 in zeolites whereas 2658 in the nanocomposites. Depends upon the LD50, therapeutic doses were estimated.
According to the delivery routes, the liver, kidney, lung, and brain may be the target organs for ZnO NPs, according to the histopathological examination (
Figure 6). The current research will also provide a deeper knowledge of the toxicity and in vivo behaviors of ZnO NPs in rats based on the different routes of administration. After a 10-day acute treatment, no abnormalities were discovered in any of the many organs that were taken for histological investigation. The liver's hepatocytes were positioned properly, and its cords and major vein were both largely patent. The kidney's glomeruli were seen to be organized normally, without any congestion or cyanosis. Normal dermal and epidermal blood vessels on the skin with no damage or congestion. The intestinal or cecal epithelium was unaffected by zeolites, zinc nanoparticles, or their nanocomposites, and no harm was seen. Additionally, there was no stenosis or damage, and the intestinal villi were orientated correctly. As demonstrated in
Figure 6, the brain's hippocampus area in particular did not exhibit any abnormal or degenerative changes. Therefore, unlike earlier studies concerning intravenous dosing of Zno NPs for a number of days, the acute oral administration of Zno NPs had resulted in that there was no inflammation or pathological lesions in the body organs [
87].
In order to increase therapeutic effectiveness, active or passive targeting, controlled or prolonged release, and decrease systemic drug adverse effects, medication delivery systems are becoming more and more common [
79]. To our knowledge, no prior research has been done on the interaction between zeolites, zinc nanoparticles, and their nanocomposites with the aim of identifying novel uses [
90]. By enabling the regulated and continuous delivery of medications, nanotechnology has shown to be helpful in the treatment of a number of biological disorders. The creation of novel materials for use in cutting-edge medical technologies as well as a rise in the targeting effectiveness of multifunctional. Nano carriers were made possible by the nanometer size. Nanoparticles or layers can include small molecules that change the efficacy, bioavailability, and safety of drugs [
91]. Drug pharmacokinetics and pharmaco-dynamics are significantly impacted by the nano carrier size and incorporation into layers [
92]. Nanoparticles enhanced the effects of carrier molecules like drugs due to their high surface-to-volume ratio. Reactive oxygen species are also produced at a higher rate under oxidative stress, which speeds up cellular activity (ROS). Zn helps achieve a high degree of activity in a short amount of time as a consequence [
93,94]. Nanoparticles containing drugs have been shown to be effective in the treatment of brain diseases and infections due to their small size particles adhering effectively and crossing the blood-brain barrier as well as their sustained or controlled release, which reduces dosing treatment and drug side effects on organ function.