High risk of intestinal colonization with ESBL-producing Escherichia coli among soldiers of military contingents in specific geographic regions.

One-hundred Polish soldiers of a contingent in Afghanistan in 2019 were screened for Enterobacterales resistant to newer-generation ß-lactams at their departure and return. Seventeen percent were colonized in the gut at the departure, whereas 70% acquired carriage in Afghanistan. The commonest organisms were extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (ESBL-Ec; 96.6%). All isolates were sequenced and were clonally diverse overall, even within the same sequence type, indicating that independent acquisitions mainly. ESBL-Ec were often multi-drug-resistant. Soldiers stationing in certain regions are at high risk of acquiring resistant bacteria that may cause endogenous infection, be transmitted to vulnerable individuals, and spread resistance genes.

The Prevalence of Intestinal Parasitic Infections Among Kosovar and Serbian School-children in Kosovo.

The aim of this study was to estimate the prevalence and distribution of species of intestinal parasites in the Balkans on the example of Kosovar and Serbian residents from the region of Gnjilane ineastern Kosovo,where the epidemiology of intestinal parasitic infections remains unknown. Parasitological examination of stools pecimens was performed in 2017 and 2018. Stool samples were collected from asymptomatic school-children aged 6-17 years: 530 Kosovars from the municipality of Kaçanik and310 Serbs from the municipalities of Kamenica and Strpce. Each patient provided two stool samples collected every second day,fixed in SAF preservative and 70 % spiritus vini, transported to the Department of Epidemiology and Tropical Medicine at the Military Institute of Medicine in Poland,and tested by light microscopy using three diagnostic methods: directs mearin Lugol's solution,decantation in distilled water, and Fülleborn's flotation. A total of 101 Kosovar children (19.1 % of the study group)were found to be infected with intestinal parasites: nematodes (n=20), cestodes (n=2), trematodes (n=2), and protozoa (n=79). Only 13 Serbian children (4.2 %) were found to beinfected with nematodes (n=4),cestodes (n=3),and protozoa (n=6). Giardia intestinalis was themost prevalent intestinal parasite in both groups (14,9 % vs. 1.9 % children). The prevalence ofasymptomatic parasitic infections was significantly higher in Kosovars in comparison to the Serbsliving in the same region of eastern Kosovo. This fact shows that there may be significant differencesin the quality of health care and sanitation as well as feed hygiene between these two communities.

Prevalence of Neisseria meningitidis Carriage with Identification of Serogroups and Genogroups in Professional Soldiers.

The article presents the prevalence of Neisseria meningitidis carriage with the identification of sero- and genogroups in professional soldiers serving in the Polish Armed Forces. A total of 1246 soldiers from the 10th Armored Cavalry Brigade in Swietoszów, Poland were examined in the period January-February 2016. Microbiological tests were performed using standard methods (culture, incubation, microscopy, biochemical, and automated identification with VITEK cards). Neisseria meningitidis isolates from carriers were subjected to a slide agglutination test for the identification of serogroups, next bacterial DNA was isolated and genogroups were identified based on the results of PCR. Of the 1246 soldiers tested, 65 were found to be carriers of N. meningitidis. Serogroups of 36 isolates and genogroups of 56 meningococcal isolates were determined. The genogrouping identified the isolates as belonging to group B (n = 34; 52.3 %), E29 (n = 8; 12.3 %), C (n = 6; 9.2 %), Y (n = 6; 9.2 %), and W (n = 2; 3.1 %). The primers which were used did not make it possible to determine the genogroup of nine isolates. In conclusion, the overall carrier rate of N. meningitidis amounted to 5.2 %, with the serogroup B being predominant, which is similar to that reported in the general population in Poland and Central Europe.

Effectiveness of immunoprophylaxis in suppressing carriage of Neisseria meningitidis in the military environment.

Neisseria meningitidis, etiological factor of invasive meningococcal disease, is a human commensal that colonizes the nasopharynx. Colonization is usually asymptomatic, but it is a prerequisite for disease. Asymptomatic carriers are the major source of infection. In the present study, a survey of N. meningitidis carriage was conducted between January and March 2013 in a military unit in Poland. Single-time throat culture samples were collected from professional 559 soldiers (302 unvaccinated vs. 257 vaccinated individuals with the quadrivalent conjugate vaccine ACYW-135). Bacterial identification was performed with classic microbiological methods (culture, incubation, identification). Non-culture method (PCR) was used for confirmation of detected strains of N. meningitidis and determination of serogroups. We found 29 carriers in the group of unvaccinated soldiers (9.6 % of examined individuals) whereas among vaccinated soldiers only 3 persons were carriers of N. meningitidis (1.2 %). The most frequently identified serogroups among the carriers serving in the same military facility were serogroup B (28 %), followed by Y (25 %), and C (22 %). In conclusion, the initiation of mass vaccination with the quadrivalent conjugate vaccine ACYW-135 in the military environment seems an effective method of suppressing N. meningitidis carriage.

Effect of inbreeding and heritability of sperm competition success in the bulb mite Rhizoglyphus robini.

Sperm competition is a potent evolutionary force shaping the reproductive biology of most animal species. Here, we estimated the heritability of sperm competition success in the promiscuous bulb mite Rhizoglyphus robini. Sperm competition success was measured with the sterile male technique as the proportion of eggs fertilised by the second of three males mated with a single female. Sperm competition success responded significantly to selection. The heritability estimated from the response to five generations of selection was 0.13. We also estimated the effect of inbreeding on sperm competition success. Males produced by sib-mating (F=0.25) had a significantly lower sperm competition success than outbred males. The estimated coefficient of inbreeding depression was 0.53. Such high inbreeding depression together with moderately low heritability is consistent with the view that sperm competitive ability is under strong directional selection and strongly influences the reproductive success of males.

Polyandry increases offspring fecundity in the bulb mite.

The common occurrence of polyandry continues to puzzle evolutionary biologists, as female reproductive success is thought to be limited mostly by her fecundity. Here we test whether females of the bulb mite, a species in which the females are highly promiscuous, benefit from polyandry in terms of increased fitness of their progeny. Females were given opportunity to mate with either one or six males, but the experiment was designed to allow the same number of matings per female in both groups, that is, irrespective of the number of males. We found that daughters of females mated to six males had significantly higher fecundity than daughters of females mated to one male, whereas other fitness components of progeny (male virility and longevity of both sexes) were not affected. These findings appear to support hypotheses proposing that multi-male mating enables females to exercise postcopulatory mate-choice (direct or indirect, via sperm competition) and thus accrue genetic benefits.