Apple cider vinegar exhibits promising antibiofilm activity against multidrug-resistant Bacillus cereus isolated from meat and their products

Background

Bacillus cereus (B. cereus) biofilm is grown not only on medical devices but also on different substrata and is considered a potential hazard in the food industry. Quorum sensing plays a serious role in the synthesis of biofilm with its surrounding extracellular matrix enabling irreversible connection of the bacteria.

Aim

The goal of the current investigation was to ascertain the prevalence, patterns of antimicrobial resistance, and capacity for B. cereus biofilm formation in meat and meat products in Egypt.

Methods

In all, 150 meat and meat product samples were used in this study. For additional bacteriological analysis, the samples were moved to the Bacteriology Laboratory. Thereafter, the antimicrobial, antiquorum sensing, and antibiofilm potential of apple cider vinegar (ACV) on B. cereus were evaluated.

Results

Out of 150 samples, 34 (22.67%) tested positive for B. cereus. According to tests for antimicrobial susceptibility, every B. cereus isolates tested positive for colistin and ampicillin but negative for ciprofloxacin and imipenem. The ability to form biofilms was present in all 12 multidrug-resistant B. cereus isolates (n = 12); of these, 6 (50%), 3 (25%), and 3 (25%) isolates were weak, moderate, and strong biofilm producers, respectively. It is noteworthy that the ACV demonstrated significant inhibitory effects on B. cereus isolates, with minimum inhibitory concentrations varying between 2 and 8 μg/ml. Furthermore, after exposing biofilm-producing B. cereus isolates to the minimum biofilm inhibitory concentrations 50 of 4 μg/ml, it demonstrated good antibiofilm activity (>50% reduction of biofilm formation). Strong biofilm producers had down-regulated biofilm genes (tasA and sipW) and their regulator (plcR) compared to the control group, according to reverse transcriptase quantitative polymerase chain reaction analysis.

Conclusion

Our study is the first report, that spotlights the ACV activity against B. cereus biofilm and its consequence as a strong antibacterial and antibiofilm agent in the food industry and human health risk.

Moringa oleifera as a potential antimicrobial against pathogenic Clostridium perfringens isolates in farm animals

Background

Clostridium perfringens (CP) is an emerging anaerobic pathogen that can aggravate severe fatal infections in different hosts and livestock.

Aim

This paper was designed to monitor the antibacterial efficacy of Moringa oleifera (M. oleifera) plant against different CP isolates of variant toxin genotypes comparing that with commercial antibiotics in the veterinary field.

Methods

A total of 200 examined fecal, intestinal, and liver samples from cattle, sheep, and goats were investigated bacteriologically and biochemically for CP. Then, the isolates were examined by polymerase chain reaction (PCR) for toxin gene typing. Thereafter, the antimicrobial susceptibility testing as well as the antibacterial efficacy of M. oleifera were evaluated and statistically analyzed against recovered isolates.

Results

The prevalence rate of CP was 51% (102/200); of which 54.5% was from cattle, 50% from sheep, and 40% from goat. Moreover, all CP isolates were highly resistant to tetracycline and lincomycin drugs; meanwhile, they were of the least resistance against ciprofloxacin (8.3%-16.7%), cefotaxime (16.7%-25%), and gentamycin (26.7%-33.3%). For M. oleifera, high antibacterial efficacy with greater inhibition zones of the plant was recorded with its oil (20-24 mm) and ethanolic extracts (16-20 mm) against CP than the aqueous extract (≤ 10 mm). A good correlation was stated between M. oleifera oil and toxin type of CP isolates particularly type A followed by D and B types. Interestingly, the oil and ethanolic extracts of M. oleifera gave higher antibacterial efficacy than most commercial antibiotics against the recovered isolates.

Conclusion

This study highlighted the potent antibacterial properties of M. oleifera for suppressing CP isolated from farm animals; hence, more investigations on M. oleifera are suggested to support its use as a medical herbal plant substituting antibiotics hazards and resistance problems worldwide.

Monitoring the genetic variation of some Escherichia coli strains in wild birds and cattle

To date, there is limited data about the genetic relationship of Escherichia coli between wild birds and cattle because these birds act as silent vectors for many zoonotic bacteria. This study aimed to elucidate the role of rooming wild birds in the vicinity of cattle farm in transmission of the same pathogenic E. coli variants, identifying their virulence, resistance traits and genetic similarities of fimH virulence gene. About 240 faecal/cloacal swabs were collected from both species and examined bacteriologically. Escherichia coli was yielded in 45.8% and 32.5%, respectively, of examined cattle and wild birds. The most prevalent detected E. coli serovar was O26. High tetracycline and chloramphenicol resistance were recorded; however, gentamycin and ciprofloxacin exhibited the highest sensitivity rates. Polymerase chain reaction (PCR) conserved genotypic resistance (tetA and blaCTX-M) and virulence attributes (fimH, stx1, eaeA and ompA) of E. coli isolates were discussed in detail. The fimH gene revealed 100% sequence similarity when comparing with different E. coli isolates globally and locally. Finally, a close genetic association of E. coli with both wild birds and cattle was detected, thus strengthening its role in the dissemination of the infection via environment. Prevention and conservative policy should be carried as E. coli constitute enormous significant zoonotic risks to livestock and animal workers. Also, further studies to the whole genome sequencing of fimH, other virulence and resistance genes of E. coli are recommended trying to limit the possibilities of co-infection and transfer among different species.Contribution: The current study recorded updated data about the critical infectious role of wild birds to livestock, including cattle farms in Egypt. It also delivered some recommendations for good hygienic practices in cattle farms which must be implemented for handling animal manure.

Curcumin loaded liposome formulation: Enhanced efficacy on performance, flesh quality, immune response with defense against Streptococcus agalactiae in Nile tilapia (Orechromis niloticus)

Application of novel trend comprising antioxidant phytogenics is aiming to minimize the stress related factors and associated diseases in intensive fish culturing. Today, the concept of exploiting and protecting natural antioxidants represents a paradigm shift for the aqua feed industry. Therefore, our principal goal targeting liposome as a novel nanocarrier for curcumin is directed to attain superior performance, fillet antioxidant stability and bacterial resistance in Nile tilapia. A total of 500 Nile tilapia fingerlings (average body weight, 10.27 ± 0.10 g) assigned into five experimental groups in 25 glass aquaria of 120 L capacity at the density 20 fish/aquaria. The experimental groups were supplemented with varying doses of liposomal curcumin-NPs, LipoCur-NPs (0, 5, 15, 25 and 35 mg/kg diet) were reared for 12 weeks and later Streptococcus agalactiae (S. agalactiae) challenged model was performed. Inclusion of LipoCur-NPs (25 and 35 mg/kg diet) had the most prominent impact on Nile tilapia growth rate and feed conversion ratio. The immune boosting outcomes post supplementing 35 mg/kg diet of LipoCur-NPs were evidenced by higher myeloperoxidase, lysozyme and total immunoglobulin levels. Even after 4 weeks frozen storage, LipoCur-NPs at the dose of 35 mg/kg diet prominently increased (P < 0.05) the fillet scavenging capability for free radicals (1,1-diphenyl-2-picrylhydrazyl and 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) with an inverse reduction in lipid peroxidation biomarker (malondialdehyde). Notably, upregulation of GSH-Px, CAT, and SOD genes in fillet of 35 mg/kg LipoCur-NPs fed fish coordinated with higher T-AOC and lower oxidative markers (ROS and H₂O₂). Post S. agalactiae challenge, higher supplementation levels of LipoCur-NPs (35 mg/kg diet) greatly attenuated the expression of its vital virulence genes (cfb, fbsA and cpsA) with higher expression of Igm, CXC-chemokine and MHC genes. Concordantly, downregulation of inflammatory markers (IL-1β, TNF-α and IL-8) and upregulation of anti-inflammatory ones (IL-10 and TGF-β) were remarkably documented. Based on these findings, the innovative curcumin loaded liposome was considered a novel multitargeting alternative not only playing an imperative role in Nile tilapia growth promotion and fillet stability upon storage, but also protecting efficiently against S. agalactiae.

Virulence and antimicrobial-resistance of shiga toxin-producing E. coli (STEC) Isolated from edible shellfish and its public health significance

Shiga toxin-producing E. coli (STEC) are an important cause of foodborne illness in humans with infections ranging from mild non-bloody diarrhea to bloody diarrhea (BD) and hemolytic uremic syndrome (HUS). This study aimed to investigate the distribution of STEC in shellfish from coastal shores of Lake Timsah in Ismailia Governorate, Egypt and its probable hazard to seafood consumers. Samples from the external surface and tissues of shrimp (n = 45), crabs (n = 45), and oysters (n = 45) batches were examined bacteriologically for the presence of STEC and tested for their antibiotic sensitivity. Moreover, occurrence of virulence genes was determined via detection of stx1, stx2 and eaeA genes using PCR. Overall, E. coli and presumptive STEC isolates (from CHROMagar) were identified from the surface (55.6 and 5.9%) and tissues (42.2 and 8.9%) of the examined shellfish batches, respectively. Five STEC isolates had been confirmed and found belonging to O26:H11, O125:H6, O146:H21, and O159 serogroups, those were 4 isolates from tissues of the three shellfish species and one isolate from the crab surface. The STEC isolates were multi-drug resistant, showing complete resistance to; penicillins, amoxycillin/clavulanic acid, colistin, fosfomycin, ceftriaxone, ciprofloxacin, and tetracycline, however, they were sensitive to gentamycin except O159 serogroup. The current study revealed low level of contamination of shellfish from coastal shores of Lake Timsah with STEC, however, it also highlights the extreme level of antimicrobial resistance exhibited by the presumptive and confirmed STEC isolates which is very hazardous for seafood consumers in the study area.

Prolactin response to thyrotropin-releasing hormone in schizoaffective depressed compared to depressed and schizophrenic men and healthy controls

Biological tests may help clarify the relationship of schizoaffective disorder to major depressive disorder (MDD) and schizophrenia (SCZ). Thyrotropin-releasing hormone (TRH), 500 micrograms, was administered intravenously to eight schizoaffective depressed (SD), ten SCZ, 23 MDD patients and 43 healthy controls (HC), all males, ages 20-66 years and drug-free. Research Diagnostic Criteria (RDC) were utilized for establishing diagnoses, Hamilton Rating Scale for Depression (HRSD) total scores were used for assessing depressive symptoms. There were no differences in dmax PRL (post-TRH prolactin peak minus baseline, mean +/- SD) amongst SD, SCZ and HC groups (27.3 +/- 5.2, 28.8 +/- 5.4 and 31.5 +/- 5.6 ng/ml respectively). Mean dmax PRL in MDD was significantly lower than each of the other three groups (17.1 +/- 2.2 ng/ml, P less than 0.05 for all). The essentially normal PRL response to TRH in SD, significantly different from MDD but similar to SCZ parallels our previous observations on the pattern of thyrotropin (TSH) response to TRH in the same diagnostic groups. These biological findings may be taken to indicate that schizoaffective disorder, depressed subtype, is closer to schizophrenia than to major depressive disorder. However, they cannot be considered definitive evidence to that effect since schizoaffective disorders are known to be quite heterogeneous, and since the utilized biological tests lack specificity.

The dexamethasone suppression test in a group of research diagnostic criteria schizoaffective depressed men

A dexamethasone suppression test (DST) was performed on 8 schizoaffective depressed men. Cross-sectional comparisons were made with three groups: schizophrenics (n = 10), unipolar major depressives (n = 23) and healthy controls (n = 43). All were drug-free and similar in age and body weight. Evaluations utilized the Research Diagnostic Criteria (RDC) for diagnosis, and the Hamilton Rating Scale for Depression for depressive symptom rating. DST nonsuppression, defined as a blood cortisol level of greater than or equal to 5.0 micrograms/dl at 16.00 h postdexamethasone, was observed in 43.5% of the major depressive disorder patients. This was different from the other three groups: 12.5% in schizoaffective depressed, 10.0% in schizophrenics and 9.3% in healthy controls (p less than 0.01, p less than 0.01, and p less than 0.001 respectively). Although schizoaffective depressed patients were significantly different from major depressive disorder patients in their DST responses, both groups were similar in their total HRSD scores and different from the schizophrenics (p less than 0.01 for each). These results, together with others previously reported by us on the thyrotropin-releasing hormone challenge in the same diagnostic groups, may be taken to mean that schizoaffective disorder, depressed type, is biologically distinct from major depressive disorder but not schizophrenia. On the other hand, until further corroborated, they should probably be considered a reflection of the heterogeneity of the schizoaffective syndrome and the nonspecificity of the DST.

Relationship of age to TSH response to TRH in depressed men

The relationship between age and TSH response to TRH was studied in 40 men with unipolar major depressive disorder (range 24-65 years, mean 44.7 years) and 36 healthy male volunteers of similar ages. Both groups were subdivided into younger and older than 40 years of age. "Blunted" TSH response to TRH was observed in 58% of depressed men and in 28% of controls, using a dTSH maximum of less than or equal to 6 microU/ml as a cut-off criterion. Older healthy men had a higher blunting rate (40%) than the younger group (19%). In depressed patients, by contrast, the blunting rate was 50% in the older group and 65% in the younger group. Higher mean maximum dTSH, higher basal TSH and lower mean circulating FT4 levels were also noted in older depressed men, suggestive of a subtle thyroid subsensitivity to TSH stimulation and subclinical primary hypothyroidism that may have contributed to the depression. Age is known to be a confounder of TRH test results. There may be a subset of depressed patients over 40 where the confounding effect of age is associated with an exaggerated, rather than decreased TSH response to TRH.

Remote tumor effects on lactic dehydrogenase of mouse muscle fibers with different glycolytic--oxidative metabolic potentials

The total lactic dehydrogenase (LD) activity and the isoenzyme pattern were studied in muscles of mice during the progressive growth of a distally transplanted methylcholanthrene-induced tumor. The thigh muscles as a group (a mixture of fibers with different oxidative-glycolytic metabolic potentials), the gastrocnemius muscle (primarily glycolytic), the soleus muscle (predominantly oxidative), the heart (purely oxidative), and the diaphragm (primarily oxidative) were evaluated. The total LD activity increased in muscles with a high glycolytic metabolic potential. In such muscles a significant increase of the muscle type and a significant decrease of the heart type of LD were observed. After 3 weeks of tumor growth the tumor was resected, and the LD activity and isoenzyme distribution returned toward normal values 2 weeks later.

Muscle and serum enzymes and isoenzymes in muscular dystrophies

Total activity of creatine kinase (CK), lactate dehydrogenase (LD), aldolase (Ald), glutamico-oxaloacetic transaminase (GOT), and LD-isoenzyme distribution was studied in serum and muscle biopsies from normal persons and 117 patients with different types of muscular dystrophy: 82 Duchenne type (DMD), 12 BEcker type, 7 facioscapulohumeral (FSHMD), and 16 limb girdle (LGMD). Total enzyme activity in sera and muscle homogenates was determined by spectrophotometric assays. LD isoenzymes were separated by electrophoresis on agarose gel plates in barbital buffer (pH 8.6), scanned and quantitated. The amounts of the 2 types (M and H) of LD isoenzymes were calculated and the ratio of M/H in serum and muscle was used as an index to differentiate among the types of muscular dystrophy. Serum enzyme activity was elevated to variable degrees reflecting a corresponding decrease in muscle enzymes in the different muscular dystrophies. Patterns of LD isoenzymes in serum and muscle were specific to each type of muscle disease. Increase in serum LD5 (the muscle LD fraction) was a common feature in muscle damage. Changes in the amounts of M and H types in the subunits of LD correlated to the existence and severity of muscle damage. The mean muscle M/H ratio was 6.4 in controls, 1.8 in early DMD, 0.1 in late DMD, 3.0 in Becker type, 3.8 in FSHMD and 3.9 in LGMD. The muscle LD isoenzyme distribution in DMD showed a shift toward a more aerobic fetal muscle pattern. This is a result of the gradual disappearance of the mature anaerobic LD-type (M) and the increase in synthesis of the aerobic fetal LD-type (H) during the progression of the disease. This report provides a comparative study of the LD isoenzyme patterns in muscular dystrophies which may help in differential diagnosis.

Changes in lactic dehydrogenase isoenzyme pattern in muscle of tumor-bearing mice

The lactic dehydrogenase isoenzyme distribution shifts gradually toward the isoenzyme pattern of the tumor in mouse muscles located distally from a transplanted mammary carcinoma.

Isoenzyme distribution of creatine kinase and lactate dehydrogenase in serum and skeletal muscle in Duchenne muscular dystrophy, collagen disease, and other muscular disorders

We determined the total activity and isoenzyme distribution of lactate dehydrogenase and creatine kinase in serum and biopsy specimens from skeletal muscle of nine normal individuals and nine patients with Duchenne muscular dystrophy (I), five with collagen disease (II), and four with non-progressive unclassified myopathy (III). Mean total serum creatine kinase in patients with Duchenne muscular dystrophy (867 U/liter, SD = 197) was 31-fold that in the control group (28 U/liter, SD = 14). There was also a small (3.3-fold) increase in the mean total serum creatine kinase of patients with III, but none in the serum from patients with II. Changes in the creatine kinase isoenzyme distribution of skeletal muscle were primarily in the MB isoenzyme. The mean percentage of creatine kinase-MB activity in muscle from patients with I (2.81, SD = 1.15) and patients with III (1.69, SD = 1.07) significantly (P less than 0.005) exceeded that of the control group (0.43, SD = 0.18). Muscle from patients with II showed little change. The most striking changes in lactate dehydrogenase were also observed in patients with I, in whom the mean total serum activity (356 U/liter, SD = 115) was 3.4-fold that of serum from the control group (105 U/liter, SD = 19). Skeletal muscle from these patients also showed a significant decrease in mean percent isoenzyme 5 activity (from 50 to 23) and an increase in that of isoenzymes 1 and 2 (from 1 to 9 and 8 to 20, respectively). These changes in the distribution of these two sets of isoenzymes in muscle were reflected in the serum.

Isoenzyme distribution of creatine kinase and lactate dehydrogenase in serum and skeletal muscle in Duchenne muscular dystrophy, collagen disease, and other muscular disorders

We determined the total activity and isoenzyme distribution of lactate dehydrogenase and creatine kinase in serum and biopsy specimens from skeletal muscle of nine normal individuals and nine patients with Duchenne muscular dystrophy (I), five with collagen disease (II), and four with non-progressive unclassified myopathy (III). Mean total serum creatine kinase in patients with Duchenne muscular dystrophy (867 U/liter, SD = 197) was 31-fold that in the control group (28 U/liter, SD = 14). There was also a small (3.3-fold) increase in the mean total serum creatine kinase of patients with III, but none in the serum from patients with II. Changes in the creatine kinase isoenzyme distribution of skeletal muscle were primarily in the MB isoenzyme. The mean percentage of creatine kinase-MB activity in muscle from patients with I (2.81, SD = 1.15) and patients with III (1.69, SD = 1.07) significantly (P less than 0.005) exceeded that of the control group (0.43, SD = 0.18). Muscle from patients with II showed little change. The most striking changes in lactate dehydrogenase were also observed in patients with I, in whom the mean total serum activity (356 U/liter, SD = 115) was 3.4-fold that of serum from the control group (105 U/liter, SD = 19). Skeletal muscle from these patients also showed a significant decrease in mean percent isoenzyme 5 activity (from 50 to 23) and an increase in that of isoenzymes 1 and 2 (from 1 to 9 and 8 to 20, respectively). These changes in the distribution of these two sets of isoenzymes in muscle were reflected in the serum.