Emerging Gram negative resistance to last-line antimicrobial agents fosfomycin, colistin and ceftazidime-avibactam – epidemiology, laboratory detection and treatment implications

Nitrofurantoin and fosfomycin for resistant urinary tract infections: old drugs for emerging problems

Uncomplicated urinary tract infection is one of the most common indications for antibiotic use in the community However the Gram-negative organisms that can cause the infection are becoming more resistant to antibiotics

Many multidrug resistant organisms retain susceptibility to two old antibiotics nitrofurantoin and fosfomycin Advantages over newer drugs include their high urinary concentrations and minimal toxicity

Fosfomycin is a potential treatment option for patients with uncomplicated urinary tract infection due to resistant organisms Nitrofurantoin may be more effective and can be used for urinary infections in pregnant women

β-lactam/β-lactamase inhibitor combinations: an update

Antibiotic resistance caused by β-lactamase production continues to present a growing challenge to the efficacy of β-lactams and their role as the most important class of clinically used antibiotics. In response to this threat however, only a handful of β-lactamase inhibitors have been introduced to the market over the past thirty years. The first-generation β-lactamase inhibitors (clavulanic acid, sulbactam and tazobactam) are all β-lactam derivatives and work primarily by inactivating class A and some class C serine β-lactamases. The newer generations of β-lactamase inhibitors including avibactam and vaborbactam are based on non-β-lactam structures and their spectrum of inhibition is extended to KPC as an important class A carbapenemase. Despite these advances several class D and virtually all important class B β-lactamases are resistant to existing inhibitors. The present review provides an overview of recent FDA-approved β-lactam/β-lactamase inhibitor combinations as well as an update on research efforts aimed at the discovery and development of novel β-lactamase inhibitors.

Phenotypic screening and molecular characterization of carbapenemase-producing Gram-negative bacilli recovered from febrile neutropenic pediatric cancer patients in Egypt

AIM

Infections with carbapenem-resistant Gram-negative bacteria (GNB) are among the most frequent complications in the immunocompromised cancer patients because of their considerable morbidity and mortality. Therefore, the aim of the current study was to characterize the prevalence of carbapenemase-producing GNB recovered from febrile neutropenic pediatric cancer patients in Egypt.

METHODS

Standard methods were used for identification, sensitivity testing (Kirby-Bauer and broth microdilution method according to CLSI guidelines). Standard methods were applied for both phenotypic and genotypic detection of the carbapenemase-producing GNB.

RESULTS

A total of 185 GNB were recovered from different clinical specimens, Escherichia (E.) coli (86; 46.48%), followed by Klebsiella spp. (71; 38.37%), Acinetobacter (A.) baumannii (7; 3.78%) and others including Pseudomonas spp., Enterobacter (Ent.) cloacae and Proteus spp. (21; 11.35%). It is a matter of concern that 116 out of 171 enterobacterial isolates (94.15%) showed resistance to three or more antimicrobial classes and were considered multidrug resistant. Additionally, the rate of carbapenem-resistance displayed a worrisome trend as 113 out of 171 enterobacterial isolates (66.08%) and 12 out of 14 non fermenting bacilli (85.71%) showed resistance pattern to at least one of the tested carbapenems. After performing a series of phenotypic tests for initial screening of potential carbapenemase producers, molecular characterization to the 29 extracted plasmids were subjected to PCR (using 5 common carbapenemase primers). The results revealed that blaOXA-48 was the most prevalent 17 (58.62%), followed by blaNDM 8(27.58%), then blaVIM 3 (10.3%) and blaKPC 2 (6.89%).

CONCLUSION

These results are an alarming threat to public health that calls for urgent application of antimicrobial stewardship programs along with routine surveillance for controlling outbreaks.