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BackgroundThe species Pectobacterium carotovorum includes a diverse subspecies of bacteria that cause disease on a wide variety of plants. In Morocco, approximately 95% of the P. carotovorum isolates from potato plants with tuber soft rot are P. carotovorum subsp. carotovorum. However, identification of this pathogen is not always related to visual disease symptoms. This is especially true when different pathogen cause similar diseases on potato, citing as an example, P. carotovorum, P. atrosepticum and P. wasabiae. Numerous conventional methods were used to characterize Pectobacterium spp., including biochemical assays, specific PCR-based tests, and construction of phylogenetic trees by using gene sequences. In this study, an alternative method is presented using a gene linked to pathogenicity, in order to allow accuracy at subspecies level. The pmrA gene (response regulator) has been used for identification and analysis of the relationships among twenty nine Pectobacterium carotovorum subsp. carotovorum and other Pectobacterium subspecies.ResultsPhylogenetic analyses of pmrA sequences compared to ERIC-PCR and 16S rDNA sequencing, demonstrated that there is considerable genetic diversity in P. carotovorum subsp. carotovorum strains, which can be divided into two distinct groups within the same clade.ConclusionspmrA sequence analysis is likely to be a reliable tool to identify the subspecies Pectobacterium carotovorum subsp. carotovorum and estimate their genetic diversity.

Pectobacterium carotovorum are economically important plant pathogens that cause plant soft rot. These enterobacteria display high diversity world-wide. Their pathogenesis depends on production and secretion of virulence factors such as plant cell wall-degrading enzymes, type III effectors, a necrosis-inducing protein, and a secreted virulence factor from Xanthomonas spp., which are tightly regulated by quorum sensing. Pectobacterium carotovorum also present pathogen-associated molecular patterns that could participate in their pathogenicity. In this study, by using suspension cells of Arabidopsis thaliana, we correlate plant cell death and pectate lyase activities during coinfection with different P. carotovorum strains. When comparing soft rot symptoms induced on potato slices with pectate lyase activities and plant cell death observed during coculture with Arabidopsis thaliana cells, the order of strain virulence was found to be the same. Therefore, Arabidopsis thaliana cells could be an alternative tool to evaluate rapidly and efficiently the virulence of different P. carotovorum strains.

Extended-spectrum β-lactamases producing Escherichia coli (ESBL-EC) lend resistance to most β-lactam antibiotics. Because of limited treatment options, ESBL-EC infections are generally more difficult to treat, leading to higher hospital costs, reduced rates of microbiological and clinical responses, and a threat to the patient’s life. This study aimed to determine the antibiotic resistance pattern of ESBL-EC isolated from patients with urinary tract infection in Morocco. This retrospective laboratory-based study was conducted at Cheikh Khalifa International University Hospital, Casablanca, from January 2016 to June 2019. A total of 670 urine samples were collected from urinary tract infection patients and processed by standard microbiological methods. In vitro susceptibility testing to different antibiotics of all identified isolates of Escherichia coli (E. coli) was performed following Kirby–Bauer’s disc diffusion method on Mueller–Hinton Agar according to the EUCAST standards. The reviewing of ESBL-EC was confirmed by the appearance of a characteristically shaped zone referred to as a “champagne cork” using the Combined Disk Test. Among a total of 438 E. coli isolated from nonrepetitive urine samples, two hundred fifty-nine (59%) were ESBL-EC, of which 200 (77%) were isolated from adult patients (over the age of 50) and the majority were female. All ESBL-EC isolates were resistant to third-generation cephalosporin and quinolones and sensitive to carbapenem and fosfomycin. Knowledge of antimicrobial resistance patterns in ESBL-EC, the major pathogen associated with urinary tract infection, is indispensable as a guide in choosing empirical antimicrobial treatment.

ObjectivesThis study aimed to investigate the nature of the amino acid motifs found in PBPs of Streptococcus pneumoniae isolates in invasive diseases from pediatric patients at Casablanca, Morocco. Five penicillin-susceptible (PSSP), ten penicillin-intermediate (PISP), and fifteen penicillin-resistant S. pneumoniae (PRSP) were studied by PCR–RFLP and DNA sequencing of the pbp1a, − 2b, and − 2x genes.ResultsThere were no changes in the conserved motifs of PBP1a, PBP2b and PBP2x for PSSP strains. Substitution close to PBP1a conserved motifs were found in all PRSP isolates and six/five PISP. Analysis of PBP2b showed that all but one of the 10 PISP strains and all PRSP had substitutions. Substitution close to PBP2x motifs showed that all but three of the 10 PISP strains and all PRSP had substitutions in tow conserved motifs. A total of 6, 11 and 10 genotypes were found after analysis of pbp1a, pbp2b, and pbp2x, respectively. The penicillin-nonsusceptible S. pneumoniae isolated in Casablanca share most amino acid substitutions of those reported worldwide, but they occurred among pneumococci with low level resistance to b-lactams.

Aims:  The early molecular events underlying the elicitation of plant defence reactions by Gram‐positive bacteria are relatively unknown. In plants, calcium and reactive oxygen species are commonly involved as cellular messengers of a wide range of biotic stimuli from pathogenic to symbiotic bacteria. In the present work, we checked whether nonpathogenic Streptomyces sp. strains could induce early signalling events leading to defence responses in BY2 tobacco cell suspensions. Methods and Results:  We have demonstrated that nonpathogenic Streptomyces sp. OE7 strain induced a cytosolic Ca2+ increase and a biphasic oxidative burst in the upstream signalling events, leading to defence responses in BY2 tobacco cell suspensions. Streptomyces sp. OE7 also elicited delayed intracellular free scopoletin production and programmed cell death. In agreement with scopoletin production, OE7 induced accumulation of PAL transcripts and increased accumulation of transcripts of EREBP1 and AOX genes that are known to be regulated by the jasmonate/ethylene pathway. Transcript levels of PR1b and NIMIN2α, both salicylic acid pathway–linked genes, were not modified. Moreover, Streptomyces sp. OE7 culture filtrates could reduce Pectobacterium carotovorum‐ and Pectobacterium atrosepticum‐induced death of BY2 cells and soft rot on potato slices. Conclusions:  New insights are thus provided into the interaction mechanisms between Streptomyces sp. and plants; Streptomyces sp. could be sensed by plant cells, and through cytosolic Ca2+ changes and the generation of reactive oxygen species, defence responses were induced. Significance and Impact of the Study:  These induced defence responses appeared to participate in attenuating Pectobacterium‐induced diseases in plants. Thus, Streptomyces sp. OE7 could be a biocontrol agent against Pectobacterium sp.

Resistance to antimicrobials and particularly multidrug resistance is one of the greatest challenges in the health system nowadays. The continual increase in the rates of antimicrobial resistance worldwide boosted by the ongoing COVID-19 pandemic poses a major public health threat. Different approaches have been employed to minimize the effect of resistance and control this threat, but the question still lingers as to their safety and efficiency. In this context, new anti-infectious approaches against multidrug resistance are being examined. Use of new antibiotics and their combination with new β-lactamase inhibitors, phage therapy, antimicrobial peptides, nanoparticles, and antisense antimicrobial therapeutics are considered as one such promising approach for overcoming bacterial resistance. In this review, we provide insights into these emerging alternative therapies that are currently being evaluated and which may be developed in the future to break the progression of antimicrobial resistance. We focus on their advantages and limitations and potential application in medicine. We further highlight the importance of the combination therapy approach, wherein two or more therapies are used in combination in order to more effectively combat infectious disease and increasing access to quality healthcare. These advances could give an alternate solution to overcome antimicrobial drug resistance. We eventually hope to provide useful information for clinicians who are seeking solutions to the problems caused by antimicrobial resistance.

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