Evolution of Antibiotic Resistance of Coagulase-Negative Staphylococci Isolated from Healthy Turkeys in Egypt: First Report of Linezolid Resistance

Coagulase-negative staphylococci (CoNS) are gaining much attention as causative agents of serious nosocomial infections in humans. This study aimed to determine the prevalence and phenotypic antimicrobial resistance of CoNS as well as the presence of resistance-associated genes in CoNS isolated from turkey farms in Egypt. Two hundred and fifty cloacal swabs were collected from apparently healthy turkeys in Egypt. Suspected isolates were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The susceptibility testing of CoNS isolates against 20 antimicrobial agents was performed using the broth microdilution test. The presence of resistance-associated genes like mecA, vanA, blaZ, erm(A), erm(B), erm(C), aac-aphD, optrA, valS, and cfr was determined. Thirty-nine CoNS were identified. All isolates were phenotypically resistant to trimethoprim/sulfamethoxazole, penicillin, ampicillin, and tetracycline. The resistance rates to erythromycin, chloramphenicol, oxacillin, daptomycin, and tigecycline were 97.4%, 94.9%, 92.3%, 89.7%, and 87.2%, respectively. Thirty-one isolates were resistant to linezolid (79.5%). Low resistance rate was detected for both imipenem and vancomycin (12.8%). The erm(C) gene was identified in all erythromycin phenotypically resistant isolates, whereas two resistant isolates possessed three resistance-conferring genes erm(A), erm(B), and erm(C). The cfr and optrA genes were detected in 11 (35.5%) and 12 (38.7%) of the 31 linezolid-resistant isolates. The mecA, aac-aphD, and blaZ genes were identified in 22.2%, 41.9%, and 2.6% of phenotypically resistant isolates to oxacillin, gentamicin, and penicillin, respectively. This is the first study revealing the correlation between linezolid resistance and presence of cfr and optrA genes in CoNS isolates from Egypt, and it can help to improve knowledge about the linezolid resistance mechanism.

Occurrence of Salmonella enterica and Escherichia coli in raw chicken and beef meat in northern Egypt and dissemination of their antibiotic resistance markers

BACKGROUND

The global incidence of foodborne infections and antibiotic resistance is recently increased and considered of public health concern. Currently, scarcely information is available on foodborne infections and ESBL associated with poultry and beef meat in Egypt.

METHODS

In total, 180 chicken and beef meat samples as well as internal organs were collected from different districts in northern Egypt. The samples were investigated for the prevalence and antibiotic resistance of Salmonella enterica serovars and Escherichia coli. All isolates were investigated for harbouring class 1 and class 2 integrons.

RESULTS

Out of 180 investigated samples 15 S. enterica (8.3%) and 21 E. coli (11.7%) were isolated and identified. S. enterica isolates were typed as 9 S. Typhimurium (60.0%), 3 S. Paratyphi A (20.0%), 2 S. Enteritidis (13.3%) and 1 S. Kentucky (6.7%). Twenty-one E. coli isolates were serotyped into O1, O18, O20, O78, O103, O119, O126, O145, O146 and O158. The phenotypic antibiotic resistance profiles of S. enterica serovars to ampicillin, cefotaxime, cefpodoxime, trimethoprim/sulphamethoxazole and tetracycline were 86.7, 80.0, 60.0, 53.3 and 40.0%, respectively. Isolated E. coli were resistant to tetracycline (80.9%), ampicillin (71.4%), streptomycin, trimethoprim/sulphamethoxazole (61.9% for each) and cefotaxime (33.3%). The dissemination of genes coding for ESBL and AmpC β-lactamase in S. enterica isolates included bla_CTX-M (73.3%), bla_TEM (73.3%) and bla_CMY (13.3%). In E. coli isolates bla_TEM, bla_CTX-M and bla_OXA were identified in 52.4, 42.9 and 14.3%, respectively. The plasmid-mediated quinolone resistance genes identified in S. enterica were qnrA (33.3%), qnrB (20.0%) and qnrS (6.7%) while qnrA and qnrB were detected in 33.3% of E. coli isolates. Class 1 integron was detected in 13.3% of S. enterica and in 14.3% of E. coli isolates. Class 2 integron as well as the colistin resistance gene mcr-1 was not found in any of E. coli or S. enterica isolates.

CONCLUSIONS

This study showed high prevalence of S. enterica and E. coli as foodborne pathogens in raw chicken and beef meat in Nile Delta, Egypt. The emergence of antimicrobial resistance in S. enterica and E. coli isolates is of public health concern in Egypt. Molecular biological investigation elucidated the presence of genes associated with antibiotic resistance as well as class 1 integron in S. enterica and E. coli.

The safety and efficacy of combined phacoemulsification and trabeculectomy with releasable sutures

AIM

To evaluate the combined phacoemulsification with acrylic intraocular lens implantation and trabeculectomy with releasable sutures, without the use of antimetabolites, performed by one surgeon.

METHODS

A retrospective analysis was performed on 251 eyes of 198 patients after a combined phaco/trabeculectomy procedure, followed up for an average of 16 months for vision, intraocular pressure (IOP), and number of glaucoma medications. Cox proportional hazard regression analysis provided measures of relative risk (RR) or hazards ratios and 95% confidence intervals (CIs) associated with the occurrence of several conditions or complications of surgery.

RESULTS

Mean preoperative variables were best corrected vision, 0.6 (SD 0.4) logMAR (20/80 Snellen); IOP, 18.7 (4.9) mm Hg; and number of glaucoma medications, 1.7 (0.8). Mean postoperative results were best corrected vision, 0.2 (0.4) logMAR (20/32 Snellen); IOP, 15.1 (3.2) mm Hg; and number of glaucoma medications, 0.3 (0.6). Postoperatively, the mean decreases from baseline were 19.2% for IOP and 84.1% for number of glaucoma medications; 85% of eyes required fewer glaucoma medications and 78% of eyes were medication free, with IOP control. There were no significant operative or postoperative complications.

CONCLUSION

Combined phacoemulsification and trabeculectomy with releasable sutures, in the absence of antimetabolites, is a safe, effective, and stable alternative for patients with cataracts and glaucoma.

Sanitation characteristics of some food processing industries

The present investigation was carried out to evaluate the sanitary conditions surrounding the food throughout the production stages in some food plants. Observation of the sanitary measures of the studied plants revealed that only 3 out of the 7 plants (42.9%) have acceptable sanitation that complies with the sanitary requirements specified by WHO. Personal hygiene and storage conditions were the most critical problems found in the studied plants. Laboratory examination of nasal and throat swabs and stool samples of workers was carried out to uncover the chronic carriers. Among the food handlers examined 46.3% were positive for intestinal parasites. Bacteriological examination of stool specimens revealed that 4.3% of carriers of Salmonella paratyphi and none were carriers of Vibreo species. Nasal swabs were also positive for Staph. aureus in 29.8% of all the examined swabs. Analysis of the main products of the studied plants revealed generally that the bacterial load of the products of plants having acceptable sanitary conditions was lower than that of the products of the other plants. The frozen vegetable products had a total aerobic mesophilic plate count ranging from 8.1 x 10(4) cfu/g in okra and 3.7 x 10(5) cfu/g in mixed vegetables. The total aerobic plate count of the ice cream (1 x 10(3) cfu/g) complies with specified Egyptian standards. However, the coliform count (9 x 10(1) MPN) was higher than the recommended limit. Lead and cadmium levels were also investigated in all products. The maximum detected level of lead was that of cream wafer (0.94 ppm) followed by banana wafer (0.82 ppm). The two detected levels were higher than Egyptian standards. The lead level in ice cream (0.19 ppm) was also higher than the specified standards. The relatively high levels of lead in cream wafer and ice cream may be attributed to more than one factor; the added color and the old machinery used in some production steps are the most accursed factors. On the other hand, the observed level of cadmium ranged between 0.046 ppm in raw mil and 0.3 ppm in soft cheese.

Effect of ischemia and reperfusion in vivo on energy metabolism of rat sciatic-tibial and caudal nerves

Our model of severe nerve ischemia consistently results in extinction of the compound nerve and muscle action potentials (NAP; CMAP) within 30 min. Since impulse transmission may depend on nerve energy metabolism (NEM), we studied the effects of ischemia with reperfusion on sciatic-tibial nerve NEM in vivo and compared these results with NEM of this nerve in deoxygenated Ringer's solution in vitro and postmortem. Ischemia for 30 min postmortem or in deoxygenated Ringer's solution resulted in marked depletion of adenosine triphosphate (ATP) and creatine phosphate (CP) and an increase in lactate (LAC) of sciatic-tibial nerve of adult male Sprague-Dawley rats. In vivo ischemia for up to 3 h to sciatic-tibial nerve was sufficient to extinguish CMAP but not NAP and did not deplete ATP, CP, or GLU nor did it increase LAC. Ischemia sufficient to extinguish NAP resulted in reduction of energy substrates to about 50% of resting. Muscle fails to conduct impulses before nerve and in vivo reductions of energy substrates are milder than in vitro changes. These changes are explainable in terms of energy requirements and supply. These findings support an energetic basis of ischemic conduction failure.