Implication of Mn-cofactored superoxide dismutase in the tolerance of swarmer Pseudomonas aeruginosa to polymixin, ciprofloxacin and meropenem antibiotics

Article

作者: Maalej, Lobna ; Ouzari, Imene-Hadda ; Chatti, Abdelwaheb ; Ben Ghorbal, Salma Kloula

The protective role of superoxide dismutase (Sod) against oxidative stress, resulting from the common antibiotic pathway of action, has been studied in the wild type and mutant strains of swarmer Pseudomonas aeruginosa, lacking Cytosolic Mn-Sod (sodM), Fe-Sod (sodB) or both Sods (sodMB).Our results showed that inactivation of sodB genes leads to significant motility defects and tolerance to meropenem. This resistance is correlated with a greater membrane unsaturation as well as an effective intervention of Mn-Sod isoform, in antibiotic tolerance.Moreover, loss of Mn-Sod in sodM mutant, leads to polymixin intolerance and is correlated with membrane unsaturation. Effectivelty, sodM mutant showed an enhanced swarming motility and a conserved rhamnolipid production. Whereas, in the double mutant sodMB, ciprofloxacin tolerance would be linked to an increase in the percentage of saturated fatty acids in the membrane, even in the absence of superoxide dismutase activity.The overall results showed that Mn-Sod has a protective role in the tolerance to antibiotics, in swarmer P.aeruginosa strain. It has been further shown that Sod intervention in antibiotic tolerance is through change in membrane fatty acid composition.

2023-05-12·BMC microbiology

Detection of multidrug-resistant Shiga toxin-producing Escherichia coli in some food products and cattle faeces in Al-Sharkia, Egypt: one health menace.

Article

作者: Nada, Hanady G ; Askora, Ahmed ; El-Didamony, Gamal ; El-Tahan, Amera Saeed

BACKGROUNDShiga toxin-producing Escherichia coli (STEC) is a zoonotic pathogen, that is transmitted from a variety of animals, especially cattle to humans via contaminated food, water, feaces or contact with infected environment or animals. The ability of STEC strains to cause gastrointestinal complications in human is due to the production of Shiga toxins (sxt). However, the transmission of multidrug-resistance STEC strains are linked with a severity of disease outcomes and horizontal spread of resistance genes in other pathogens. The result of this has emerged as a significant threat to public health, animal health, food safety, and the environment. Therefore, the purpose of this study is to investigate the antibiogram profile of enteric E. coli O157 isolated from food products and cattle faeces samples in Zagazig City, Al-Sharkia, Egypt, and to reveal the presence of Shiga toxin genes stx1 and stx2 as virulence factors in multidrug-resistant isolates. In addition to this, the partial 16S rRNA sequencing was used for the identification and genetic recoding of the obtained STEC isolates.RESULTSThere was a total of sixty-five samples collected from different geographical regions at Zagazig City, Al-Sharkia-Egypt, which were divided into: 15 chicken meat (C), 10 luncheon (L), 10 hamburgers (H), and 30 cattle faeces (CF). From the sixty-five samples, only 10 samples (one from H, and 9 from CF) were identified as suspicious E. coli O157 with colourless colonies on sorbitol MacConkey agar media with Cefixime- Telurite supplement at the last step of most probable number (MPN) technique. Eight isolates (all from CF) were identified as multidrug-resistant (MDR) as they showed resistance to three antibiotics with multiple antibiotic resistance (MAR) index ≥ 0.23, which were assessed by standard Kirby-Bauer disc diffusion method. These eight isolates demonstrated complete resistance (100%) against amoxicillin/clavulanic acid, and high frequencies of resistance (90%, 70%, 60%,60%, and 40%) against cefoxitin, polymixin, erythromycin, ceftazidime, and piperacillin, respectively. Those eight MDR E. coli O157 underwent serological assay to confirm their serotype. Only two isolates (CF8, and CF13), both from CF, were showed strong agglutination with antisera O157 and H7, as well as resistance against 8 out of 13 of the used antibiotics with the highest MAR index (0.62). The presence of virulence genes Shiga toxins (stx1 and stx2) was assessed by PCR technique. CF8 was confirmed for carrying stx2, while CF13 was carrying both genes stx1, and stx2. Both isolates were identified by partial molecular 16S rRNA sequencing and have an accession number (Acc. No.) of LC666912, and LC666913 on gene bank. Phylogenetic analysis showed that CF8, and CF13 were highly homologous (98%) to E. coli H7 strain, and (100%) to E. coli DH7, respectively.CONCLUSIONThe results of this study provides evidence for the occurrence of E. coli O157:H7 that carries Shiga toxins stx1 and/or stx2, with a high frequency of resistance to antibiotics commonly used in human and veterinary medicine, in Zagazig City, Al-Sharkia, Egypt. This has a high extent of public health risk posed by animal reservoirs and food products with respect to easy transmission causing outbreaks and transfer resistance genes to other pathogens in animal, human, and plants. Therefore, environmental, animal husbandry, and food product surveillance, as well as, clinical infection control, must be strengthened to avoid the extra spread of MDR pathogens, especially MDR STEC strains.

2023-01-01·PloS one

Antibiotic resistance and virulence genes profiling of Vibrio cholerae and Vibrio mimicus isolates from some seafood collected at the aquatic environment and wet markets in Eastern Cape Province, South Africa.

Article

作者: Osunla, Charles A ; Abioye, Oluwatayo E ; Nontongana, Nolonwabo ; Okoh, Anthony I

The current study determines the density of Vibrio spp. and isolates V. cholerae and Vibrio mimicus from fish-anatomical-sites, prawn, crab and mussel samples recovered from fish markets, freshwater and brackish water. Virulence and antibiotic resistance profiling of isolates were carried out using standard molecular and microbiology techniques. Vibrio spp. was detected in more than 90% of samples [134/144] and its density was significantly more in fish than in other samples. Vibrio. cholerae and V. mimicus were isolated in at least one sample of each sample type with higher isolation frequency in fish samples. All the V. cholerae isolates belong to non-O1/non-O139 serogroup. One or more V. cholerae isolates exhibited intermediate or resistance against each of the eighteen panels of antibiotics used but 100% of the V. mimicus were susceptible to amikacin, gentamycin and chloramphenicol. Vibrio cholerae exhibited relatively high resistance against polymyxin, ampicillin and amoxicillin/clavulanate while V. mimicus isolates exhibited relatively high resistance against nitrofurantoin, ampicillin and polymixin. The multiple-antibiotic-resistance-index [MARI] for isolates ranges between 0 and 0.67 and 48% of the isolates have MARI that is >0.2 while 55% of the isolates exhibit MultiDrug Resistance Phenotypes. The percentage detection of acc, ant, drf18, sul1, mcr-1, blasvh, blaoxa, blatem, blaoxa48, gyrA, gyrB and parC resistance-associated genes were 2%, 9%, 14%, 7%, 2%, 25%, 7%, 2%, 2%, 32%, 25% and 27% respectively while that for virulence-associated genes in increasing other was ace [2%], tcp [11%], vpi [16%], ompU [34%], toxR [43%], rtxC [70%], rtxA [73%] and hyla [77%]. The study confirmed the potential of environmental non-O1/non-O139 V. cholerae and V. mimicus to cause cholera-like infection and other vibriosis which could be difficult to manage with commonly recommended antibiotics. Thus, regular monitoring of the environment to create necessary awareness for this kind of pathogens is important in the interest of public health.

100 项与 Polymixin derivatives (Northern Antibiotics) 相关的药物交易

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