RESUMEN
OBJECTIVES: Pseudomonas aeruginosa and Acinetobacter baumannii resist antibiotics by different intrinsic and acquired mechanisms. This study aims to define various carbapenem-resistant mechanisms of isolated P. aeruginosa and A. baumannii from nine different provinces of Iran. MATERIALS AND METHODS: In this cross-sectional study, all carbapenem-resistant P. aeruginosa and A. baumannii samples from nine provinces of Iran on a one-year time horizon were gathered. Modified Hedge Test (MHT) and Carba NP-Test were applied to the identification of producing-carbapenemase strains. The most important carbapenemase genes recognized by PCR and gene overexpression of the efflux pump were surveyed by efflux pump inhibitors (EPIs) and confirmed by Real-Time PCR. RESULTS: Twenty-one percent and 43.5% of P. aeruginosa and A. baumannii isolates were resistant to carbapenem, respectively. MHT and Carba-NP tests identified 21% and 11% carbapenemase-producing strains in these Gram-negative bacteria, respectively. NDM-1 was the most prevalently detected carbapenemase in P. aeruginosa; OXA-51 and OXA-23 were the most significant genes in A. baumannii. EPIs identified active efflux pumps in 20% and 28% of P. aeruginosa and A. baumannii, respectively. Real-time PCR confirmed gene overexpression of efflux pumps in 54% and 30% of positive EPIs in P. aeruginosa and A. baumannii, respectively. CONCLUSION: P. aeruginosa and A. baumannii may become multi-drug-resistant (MDR) and Extensively Drug-Resistant (XDR) strains and cause a high rate of mortality and morbidity. Thus, it is of necessity to prohibit the spread of antibiotic-resistant strains in hospitals.
RESUMEN
BACKGROUND: Rattus norvegicus are reservoirs for transmission of various zoonotic parasites, and they have become a threat to public health worldwide. Given the large number and the significant presence of R. norvegicus throughout the city of Tehran, this study aims to assess the frequency of zoonotic parasites carried by commensal rodents wandering in Tehran, Iran. The study considered the north, south, west, east, and center regions of Tehran for the purposes of this study. The serological tests were applied in order to detect effective antibodies against Trichomonas vaginalis (T. vaginalis), Babesia spp., and Cryptosporidium spp. using a commercial qualitative rat ELISA kit. The frequency of Toxoplasma gondii (T. gondii) was surveyed by using the conventional PCR method. Furthermore, nested PCR was employed to detect the presence of Giardia spp. and Leishmania spp. in commensal R. norvegicus dispersed in Tehran. RESULTS: Approximately, 76% of the 100 R. norvegicus tested were infected with at least one zoonotic parasite, indicating the significant frequency of parasites within the study areas. Seroreactivity against T. vaginalis, Babesia spp., and Cryptosporidium spp. was detected in 5%, 0%, and 1% of the R. norvegicus tested, respectively. T. gondii DNA was detected in 32 out of 100 (32%) R. norvegicus. In addition, Leishmania spp. and Giardia spp. DNA were found in 18 out of 100 (18%) and 76 out of 100 (76%) R. norvegicus investigated, respectively. T. vaginalis with 15% and T. gondii with 70% had the highest frequency of parasites among the R. norvegicus collected from the western and northeastern regions of Tehran, respectively. Moreover, Giardia spp. with 95% and Leishmania spp. with 30% had the highest frequency in the east and center districts, respectively. CONCLUSION: The findings showed a wide geographical dissemination of Giardia spp., Toxoplasma gondii, and Leishmania spp. in R. norvegicus within five districts of Tehran. In contrast, other parasites such as Cryptosporidium spp. infection were rarely detected in Rattus populations. No evidence for the circulation of Babesia spp. was found in this study.