الفهرس 
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Abstract
Powdered infant formula was first thought to be the only source of infantile infection. However, it is now clear that contamination of reconstituted PIF can occur intrinsically and extrinsically.
This study was aimed to the isolation and identification of Campylobacter spp. from PIF and symptomatic infants’ stools who were admitted to Assiut University Children’s Hospital (Gastroenterology and Hepatology Unit) and fed on this infant formula. Also, this study seeks to determine the incidence of Campylobacter spp. among PIF and patients, the susceptibility of Campylobacter spp. isolates to antibiotics, and the molecular detection of antibiotic resistance genes in isolated Campylobacter strains from PIF and infants’ stools.
A total of 172 samples were collected, which included 86 samples of powdered infant formula (PIF) and 86 stool swabs from symptomatic infants who fed on these formulas at Gastroenterology and Hepatology Unit of Assiut University Children Hospital. Campylobacter isolates were detected through conventional methods, including culture, motility test and some biochemical tests, including catalase, oxidase, and hippurate hydrolysis tests. For the confirmation of Campylobacter spp. isolates, PCR was carried out.
This investigation revealed that the total frequency of positive Campylobacter spp. isolates from PIF samples was 11.6% (10 Campylobacter isolates), which represent 10.5%, 15.6%, zero percent, and 11.1% according to age groups as 1-3 months, >3-6 months, >6-9 months, and 9-12 months, respectively. The collected stool samples revealed a total frequency of 24.4% positive samples for Campylobacter spp. The frequency of these isolates was 26.3%, 24.4%, 23.1%, and 22.2% according to age groups as 1-3 months, >3-6 months, >6-9 months, and 9-12 months, respectively. According to the PIF isolates, 50% were C. jejuni and 50% were non-C. jejuni, while for the stool isolates, 81% were C. jejuni and 19% were non-C. jejuni.
The frequency of Campylobacter spp. isolates from infants’ stools was 24.4% (21 Campylobacter isolates), which included 21.7% males and 27.5% females, 24.4% infants from rural areas and 25% came from urban locations, 26.2% infants dependent on PIF feeding with no breast feeding and 20% infants dependent on both PIF and breast feeding, 26.5% with a history of cesarean section delivery, 16.7% with a history of normal vaginal delivery, 31.3% with a history of neonatal intensive care unit admission, and 20.4% didn’t.
The frequency of Campylobacter spp. isolates in examined infants’ stool according to times of diarrhea per day (4-6, 7-10, and >10 times per day) were 31.4%, 22.2%, and 16.7%, respectively, while according to times of vomiting per day in infected infants were 20%, 40%, and 29% in 4-6, 7-10, and >10 (persistent or after each feed) vomiting times per day, respectively. Finally, 20% of infants didn’t vomit. The frequency of Campylobacter spp. isolates from symptomatic infants was 33.3% had bloody diarrhea, 20% had diarrhea with mucus, 26.2% had a fever over 38°C, 19% of infants had no fever, and 25% were dehydrated.
An antimicrobial susceptibility test of Campylobacter spp. isolates from PIF by the Kirby-Bauer disc diffusion method was carried out and revealed 100% resistance to each of Tetracycline, Erythromycin, Azithromycin, and Clindamycin. Each of (Ampicillin\sulbactam), Ceftriaxone, Cefoperazone, and doxycycline exhibited a resistance pattern of 70%. Only imipenem was 50%, while meropenem and Co-trimoxazole were 40%. (Amoxicillin/clavulanic acid), Cefpodoxime, Ciprofloxacin, and Levofloxacin demonstrated a resistance pattern of 30%; on the other hand, Gentamycin and Amikacin had the least resistance pattern of 10%.
According to infants’ stools, Campylobacter spp. isolates revealed that resistance rates of Erythromycin and Clindamycin were 100%, followed by Azithromycin at 95.2%. Both Tetracycline and (Ampicillin\sulbactam) exhibited a high resistance rate of 81%, followed by Doxycycline at 66.7%. More than half of Campylobacter spp. isolates were resistant to Co-trimoxazole (Amoxicillin\clavulanic acid), Ceftriaxone, Cefoperazone, and Imipenem, with a rate of 57.1%, 57%, 52.4%, 52.4%, and 52.4%, respectively, while Meropenem had a rate of 42.9%. Both Ciprofloxacin and Cefpodoxime showed a resistance pattern of 38.1%; on the other hand, Levofloxacin showed a resistance pattern of 28.6%.
In this study, the Aminoglycoside antibiotic group, including both Gentamycin and Amikacin, exhibited the most effective antimicrobial agents against Campylobacter strains, with a resistance pattern of 9.2% and 4.8%, respectively.
Unfortunately, multidrug-resistant Campylobacter strains were found to be 90% and 90.48% in PIF and infants’ stool isolates, respectively, as follows:
Thirty percent from PIF and 4.8% from infants’ stools were resistant to three classes of antibiotics, while 30% from PIF and 33.3% from infants’ stools, respectively, are resistant to four classes. The frequency of multidrug-resistant Campylobacter spp. from PIF and infants’ stools was 10% and 42.9%, respectively, resistant to five classes of antibiotics, and 20% and 9.5%, respectively, resistant to six classes. The multidrug-resistant Campylobacter spp. isolates from PIF and infants’ stools were mostly resistant to four and five classes of antibiotics, with a percentage of 32.25% for both.
The other strains were pan-drug resistant, with a pattern of 10% from PIF and 9.5% from infants’ stools, which are resistant to seven classes of antibiotics.
According to molecular identification of Campylobacter spp. resistant genes, the frequency of Campylobacter isolates from PIF carrying Blaoxa-61, 23s rRNA, and TetO genes was 40% for each, while 60% carried GyrA gene. On the other hand, the frequency of Campylobacter isolates from infants’ stools was 76.5% carrying Blaoxa-61 and GyrA genes for each, while 41.2% and 29.4% carried the 23s rRNA and TetO genes, respectively.
Genotypic detection of multidrug-resistant Campylobacter spp. isolates from PIF was 20%, all positive for three genes, while Campylobacter isolates from infants’ stools expressed a pattern of 33.3%, which divided to 19% carrying three genes and 14.3% carrying four genes.